UI:

* Screen level regions created for menus are now a separate
  CTX_wm_menu in the context, so they don't interfere with
  existing regions.
* Fix context in popup menus to always come from the area
  and region the popup was opened from.
* Removed some unused context stuff: tasks and reports.
  The places that were using context reports were using it
  wrong anyway.
* Fix F6 closing immediately after editing a button, by
  making uiBlockSetFlag not clear existing flags anymore.
* Don't use ":" in boolean X/Y/Z buttons.

source/blender/blenkernel/intern/blender.c

@@ -348,7 +348,7 @@ static void setup_app_data(bContext *C, BlendFileData *bfd, char *filename)
 		CTX_data_scene_set(C, bfd->curscreen->scene);
 		CTX_wm_area_set(C, NULL);
 		CTX_wm_region_set(C, NULL);
-		CTX_wm_ui_block_set(C, NULL, NULL);
+		CTX_wm_menu_set(C, NULL);
 	}
 	
 	/* this can happen when active scene was lib-linked, and doesnt exist anymore */