Commands refactor, first pass.

- add API versionning
- changed error handling, based on exception
- commands moved/merged from mod_admin_p1 to mod_admin_extra
- command bufixes
- add some elixir unit test cases

Squashed commit of the following:

commit dd59855b3486f78a9349756e4f102e79b3accff8
Merge: 14e8ffc 506e08e
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Fri Oct 30 11:43:18 2015 +0100

    Merge branch '3.2.x' into api

commit 14e8ffce78cbea6c8605371d1fc50a0c1d1e012c
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Tue Oct 27 16:35:17 2015 +0100

    Added OAuth tests to ejabberd_commands

commit f81c550c14628edfe4861c228576cb767924366a
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Tue Oct 27 16:34:55 2015 +0100

    Added some mod_http_api tests

commit 6a64578d5b2ba532a2feb6503ed98561e56d5d53
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Mon Oct 26 15:29:36 2015 +0100

    Fix get_last command test

    Previous version won't work with dst.

commit 27e0cde9e9c1f001effe68f8424a365ad947c068
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Fri Oct 23 17:59:34 2015 +0200

    Add tests on admin command policy

commit 19dad8d54f54c9fabd454280483cccfb06c8e78a
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Fri Oct 23 16:49:36 2015 +0200

    Added command related tests (http api & user policy)

commit e0e596ab4a3f3a70aba5f374f028939ab794de33
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Fri Oct 23 16:49:16 2015 +0200

    Fix command call.

commit 128cd7d1ede3c47a34f8ec3a750c980ccad2c61d
Merge: 60c4c4c 447313c
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Thu Oct 22 14:48:39 2015 +0200

    Merge branch '3.2.x' into api

commit 60c4c4c0751302524c14219c6bc8c56a6069a689
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Thu Oct 22 14:45:57 2015 +0200

    Fix ejabberd_commands spec.

commit 8e145c28c5da762c2b93ee32327eff1db94ebfed
Merge: 397273a f13dc94
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Wed Oct 21 18:26:07 2015 +0200

    Merge branch '3.2.x' into api

commit 397273a23ed415feac87aed33da6452229793387
Merge: c30e89b f289e27
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Wed Oct 21 15:27:45 2015 +0200

    Merge branch '3.2.x' into api

commit c30e89bb8a0013bff37e61e4c6953350c9c1f313
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Wed Oct 21 12:47:02 2015 +0200

    Merge mod_http_api

commit 7b0db22b4acd48ff6fabce41c1b2525e6580a3c5
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Fri Oct 16 11:55:48 2015 +0200

    Fix exunit tests to run with common_test suites

commit d8b1a89800ac7379a57a7eb4a09c3c93c3e1e5eb
Merge: 2879ae8 63455b3
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Thu Oct 15 11:39:45 2015 +0200

    Merge branch '3.2.x' into api

commit 2879ae87ff3eee369ef3d780136b96ecff5285d1
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Wed Oct 14 14:53:44 2015 +0200

    Fix update_roster command.

commit a1d453dd7a3afda9861a8d747494a45057ad574b
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Tue Oct 13 16:14:28 2015 +0200

    API commands refactor

    Moving and/or merging commands from mod_admin_p1 to mod_admin_extra

commit b709ed26b0fc0ca4f3bdd5a59fa58ec7e3db97fa
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Wed Oct 7 15:10:01 2015 +0200

    Add tests on commands

commit 6711687bee9c672cb3d5aed0744e13420ecf6dbd
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Tue Sep 29 15:58:16 2015 +0200

    Add ejabberd_commands tests

commit df8682f419cf3877e77e36a19bca0fc55dc991f8
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Mon Sep 28 14:54:39 2015 +0200

    Added API versioning for ejabberdctl and rest commands

commit cd017b0e3aac431bc3ee807ceb7f8641e1523ef5
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Fri Sep 18 11:21:45 2015 +0200

    Better error handling of HTTP API commands.

commit ca5cb6acd8e4643f9d6c484d2277b0d7e88471e5
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Tue Sep 15 15:03:05 2015 +0200

    add commands to mod_admin_extra:
    - get_offline_count
    - get_presence
    - change_password

commit 7f583fa099e30ac2b0915669fd8f102ac565b833
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Tue Sep 15 15:02:16 2015 +0200

    Improve REST API error handling

commit 14753b1c02cdce434a786b7f80f6c09f0d210075
Author: Jerome Sautret <jerome.sautret@process-one.net>
Date:   Mon Sep 14 10:51:17 2015 +0200

    Change REST API return codes for integer type.

1 files changed, 192 insertions, 0 deletions

diff --git a/test/mod_roster_mock.exs b/test/mod_roster_mock.exs
new file mode 100644
index 00000000..b4991cfd
--- /dev/null
+++ b/test/mod_roster_mock.exs
@@ -0,0 +1,192 @@
+	#  mod_roster mock
+	######################
+
+defmodule ModRosterMock do
+	@author "jsautret@process-one.net"
+
+	require Record
+	Record.defrecord :roster, Record.extract(:roster,
+																					 from: "mod_roster.hrl")
+
+	@agent __MODULE__
+
+	def init(domain, module) do
+		try do
+			Agent.stop(@agent)
+		catch
+			:exit, _e -> :ok
+		end
+
+		{:ok, _pid} = Agent.start_link(fn -> %{} end, name: @agent)
+
+		mock_with_moka module
+
+		#:mod_roster.stop(domain)
+		:mod_roster.start(domain, [])
+	end
+
+	def mock_with_moka(module) do
+		try do
+
+			module_mock = :moka.start(module)
+			:moka.replace(module_mock, :mod_roster, :invalidate_roster_cache,
+				fn (_user, _server)  ->
+					:ok
+				end)
+
+			:moka.load(module_mock)
+
+			roster_mock = :moka.start(:mod_roster)
+
+			:moka.replace(roster_mock, :gen_mod, :db_type,
+				fn (_host, _opts)  ->
+					{:none}
+				end)
+
+			:moka.replace(roster_mock, :gen_iq_handler, :add_iq_handler,
+				fn (_module, _host, _ns, _m, _f, _iqdisc)  ->
+					:ok
+				end)
+
+			:moka.replace(roster_mock, :gen_iq_handler, :remove_iq_handler,
+				fn (_module, _host, _ns)  ->
+					:ok
+				end)
+
+			:moka.replace(roster_mock, :transaction,
+				fn (_server, function)  ->
+					{:atomic, function.()}
+				end)
+
+			:moka.replace(roster_mock, :get_roster,
+				fn (user, domain)  ->
+					to_records(get_roster(user, domain))
+				end)
+
+			:moka.replace(roster_mock, :update_roster_t,
+				fn (user, domain, {u, d, _r}, item)  ->
+					add_roster_item(user, domain, u<>"@"<>d,
+													roster(item, :name),
+													roster(item, :subscription),
+													roster(item, :groups),
+													roster(item, :ask),
+													roster(item, :askmessage))
+				end)
+
+			:moka.replace(roster_mock, :del_roster_t,
+				fn (user, domain, jid)  ->
+					remove_roster_item(user, domain, :jlib.jid_to_string(jid))
+				end)
+
+			:moka.load(roster_mock)
+
+		catch
+			{:already_started, _pid} -> :ok
+		end
+
+	end
+
+	def	mock_with_meck do
+#		mock(:gen_mod, :db_type,
+#			fn (_server, :mod_roster)  ->
+#				:mnesia
+#				 end)
+#
+#		mock(:mnesia, :transaction,
+#			fn (_server, function)  ->
+#				{:atomic, function.()}
+#			end)
+#
+#		mock(:mnesia, :write,
+#			fn (Item)  ->
+#				throw Item
+#				{:atomic, :ok}
+#			end)
+
+		mock(:mod_roster, :transaction,
+			fn (_server, function)  ->
+				{:atomic, function.()}
+			end)
+
+		mock(:mod_roster, :update_roster_t,
+				 fn (user, domain, {u, d, _r}, item) ->
+					 add_roster_item(user, domain, u<>"@"<>d,
+													 roster(item, :name),
+													 roster(item, :subscription),
+													 roster(item, :groups),
+													 roster(item, :ask),
+													 roster(item, :askmessage))
+				 end)
+
+		mock(:mod_roster, :invalidate_roster_cache,
+			fn (_user, _server)  ->
+				:ok
+			end)
+
+	end
+
+	def add_roster_item(user, domain, jid, nick, subs \\ :none, groups \\ [],
+											ask \\ :none, askmessage \\ "")
+	when is_binary(user) and byte_size(user) > 0
+	and  is_binary(domain) and byte_size(domain) > 0
+	and  is_binary(jid) and byte_size(jid) > 0
+	and  is_binary(nick)
+	and  is_atom(subs)
+	and  is_list(groups)
+	and  is_atom(ask)
+	and  is_binary(askmessage)
+		do
+		Agent.update(@agent, fn roster ->
+			Map.put(roster, {user, domain, jid}, %{nick: nick,
+																						 subs: subs, groups: groups,
+																						 ask: ask,	askmessage: askmessage})
+		end)
+	end
+
+	def remove_roster_item(user, domain, jid) do
+		Agent.update(@agent, fn roster ->
+			Map.delete(roster, {user, domain, jid})
+		end)
+	end
+
+	def get_rosters() do
+		Agent.get(@agent, fn roster -> roster end)
+	end
+
+	def get_roster(user, domain) do
+		Agent.get(@agent, fn roster ->
+		for {u, d, jid} <- Map.keys(roster), u == user, d == domain,
+				do: {{u, d, jid}, Map.fetch!(roster, {u, d, jid})}
+		end)
+	end
+
+	def	to_record({{user, domain, jid}, r}) do
+		roster(usj: {user, domain, jid},
+					 us: {user, domain},
+					 jid: :jlib.string_to_usr(jid),
+					 subscription: r.subs,
+					 ask: r.ask,
+					 groups: r.groups,
+					 askmessage: r.askmessage
+		)
+	end
+	def to_records(rosters) do
+		for item <- rosters, do: to_record(item)
+	end
+
+####################################################################
+#     Helpers
+####################################################################
+
+	# TODO refactor: Move to ejabberd_test_mock
+	def mock(module, function, fun) do
+		try do
+			:meck.new(module, [:non_strict, :passthrough, :unstick])
+		catch
+			:error, {:already_started, _pid} -> :ok
+		end
+
+		:meck.expect(module, function, fun)
+	end
+
+end