[#18678] Swizzle properties for Mathutils.Vector

patch from Alex Fraser (z0r)

eg.
  - vec.xyz = vec.zyx
  - vec.xy = vec.zw
  - vec.xxy = vec.wzz
  - vec.yzyz = vec.yxyx

See http://en.wikipedia.org/wiki/Swizzling_(computer_graphics)

made some minor modifications to this patch.

tested access times and adding 336 attributes to vectors doesn't make a noticeable differences to speed of existing axis attributes (x,y,z,w) - thanks to python dict lookups.

source/gameengine/Ketsji/KX_PythonInit.cpp

@@ -1708,6 +1708,9 @@ void exitGamePlayerPythonScripting()
 	/* since python restarts we cant let the python backup of the sys.path hang around in a global pointer */
 	restorePySysPath(); /* get back the original sys.path and clear the backup */
 	
+	/* Modules that need freeing */
+	Mathutils_Free(NULL); 
+	
 	Py_Finalize();
 	bpy_import_main_set(NULL);
 }