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

doc/python_api/sphinx_doc_gen.py

@@ -614,6 +614,10 @@ def pyfunc2sphinx(ident, fw, identifier, py_func, is_class=True):
     '''
     function or class method to sphinx
     '''
+    
+    if type(py_func) == type(bpy.types.Space.draw_handler_add):
+        return
+    
     arg_str = inspect.formatargspec(*inspect.getargspec(py_func))
 
     if not is_class: