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/python/generic/py_capi_utils.h

@@ -76,7 +76,7 @@ PyObject *      PyC_UnicodeFromByteAndSize(const char *str, Py_ssize_t size);
 const char *    PyC_UnicodeAsByte(PyObject *py_str, PyObject **coerce); /* coerce must be NULL */
 const char *    PyC_UnicodeAsByteAndSize(PyObject *py_str, Py_ssize_t *size, PyObject **coerce);
 
-/* name namespace function for bpy & bge */
+/* name namespace function for bpy */
 PyObject *		PyC_DefaultNameSpace(const char *filename);
 void			PyC_RunQuicky(const char *filepath, int n, ...);