Blender Git Loki

python modules in the game engine could point to builtin modules like GameLogic that was cleared.
I added module clearing before there was checks for invalid python objects, so now its not needed for BGE Builtin types at least.

also made the builtin modules get re-used if they already exist and clear all user modules when the game engine finishes so with Module-Py-Controllers the referenced modules are at least up to date when pressing Pkey.