Removing Blender Game Engine from Blender 2.8

Folders removed entirely:
* //extern/recastnavigation
* //intern/decklink
* //intern/moto
* //source/blender/editors/space_logic
* //source/blenderplayer
* //source/gameengine

This includes DNA data and any reference to the BGE code in Blender itself.
We are bumping the subversion.

Pending tasks:
* Tile/clamp code in image editor draw code.
* Viewport drawing code (so much of this will go away because of BI removal
  that we can wait until then to remove this.

source/blender/windowmanager/CMakeLists.txt

@@ -42,7 +42,6 @@ set(INC
 	../makesrna
 	../nodes
 	../render/extern/include
-	../../gameengine/BlenderRoutines
 	../../../intern/clog
 	../../../intern/ghost
 	../../../intern/guardedalloc
@@ -143,10 +142,6 @@ if(WITH_PYTHON)
 	add_definitions(-DWITH_PYTHON)
 endif()
 
-if(WITH_GAMEENGINE)
-	add_definitions(-DWITH_GAMEENGINE)
-endif()
-
 if(WITH_BUILDINFO)
 	add_definitions(-DWITH_BUILDINFO)
 endif()