facebook: remove the featute from the code base

Remove from:
- unit tests
- desktop widgets
- preferences
- core intergration
- cmakefiles
- build scripts
- icons
- docs

Also remove the plugins and social network integration.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>

desktop-widgets/CMakeLists.txt

@@ -7,20 +7,12 @@ if(BTSUPPORT)
 	set(BT_SRC_FILES btdeviceselectiondialog.cpp)
 endif()
 
-if (FBSUPPORT)
-	add_definitions(-DFBSUPPORT)
-endif()
-
-
 include_directories(.
 	${CMAKE_CURRENT_BINARY_DIR}
 	${CMAKE_BINARY_DIR}
 )
 
 add_subdirectory(preferences)
-if(NOT DISABLE_PLUGINS)
-	add_subdirectory(plugins)
-endif()
 
 set (SUBSURFACE_UI
 	about.ui