Merged changes in the trunk up to revision 53584.

Conflicts resolved:
release/scripts/startup/bl_ui/properties_render.py
source/blender/blenloader/intern/readfile.c
source/blender/editors/interface/interface_templates.c
source/blender/makesrna/RNA_enum_types.h

Also made additional code updates for:
r53355 UIList - Python-extendable list of UI items
r53460 Alpha premul pipeline cleanup

source/creator/creator.c

@@ -1420,7 +1420,7 @@ int main(int argc, const char **argv)
 	WM_main(C);
 
 	return 0;
-} /* end of int main(argc,argv)	*/
+} /* end of int main(argc, argv)	*/
 
 #ifdef WITH_PYTHON_MODULE
 void main_python_exit(void)