Improved performance of shutting down the engine

git-svn-id: http://svn.code.sf.net/p/angelscript/code/trunk/sdk@2004 404ce1b2-830e-0410-a2e2-b09542c77caf
Store the owning module pointer in interfaces, enums, and typedefs

git-svn-id: http://svn.code.sf.net/p/angelscript/code/trunk/sdk@2005 404ce1b2-830e-0410-a2e2-b09542c77caf