Install docs into share/doc/ rather than include/

--- CMakeLists.txt.orig	2016-01-19 00:21:32 UTC
+++ CMakeLists.txt
@@ -91,7 +91,7 @@ else()
     if(WIN32)
         set(MAN_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/man/man1)
     else()
-        set(MAN_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/share/man/man1)
+        set(MAN_INSTALL_DIR ${CMAKE_INSTALL_PREFIX}/man/man1)
     endif()
 endif()
 if(DOC_INSTALL_DIR)
@@ -616,9 +616,9 @@ install(TARGETS ${qhull_TARGETS_INSTALL}
         ARCHIVE DESTINATION ${LIB_INSTALL_DIR})
 
 install(FILES ${libqhull_HEADERS}    DESTINATION ${INCLUDE_INSTALL_DIR}/libqhull)
-install(FILES ${libqhull_DOC}        DESTINATION ${INCLUDE_INSTALL_DIR}/libqhull)
+install(FILES ${libqhull_DOC}        DESTINATION ${DOC_INSTALL_DIR}/libqhull)
 install(FILES ${libqhullr_HEADERS}    DESTINATION ${INCLUDE_INSTALL_DIR}/libqhull_r)
-install(FILES ${libqhullr_DOC}        DESTINATION ${INCLUDE_INSTALL_DIR}/libqhull_r)
+install(FILES ${libqhullr_DOC}        DESTINATION ${DOC_INSTALL_DIR}/libqhull_r)
 install(FILES ${libqhullcpp_HEADERS} DESTINATION ${INCLUDE_INSTALL_DIR}/libqhullcpp)
 install(FILES html/qhull.man         DESTINATION ${MAN_INSTALL_DIR} RENAME qhull.1)
 install(FILES html/rbox.man          DESTINATION ${MAN_INSTALL_DIR} RENAME rbox.1)