Action/Shapekey Editor Bugfixes:

* Shapekey editor now shows ID-box for showing and editing the action assigned here. This should help alleviate the misconceptions arising to #23823, where user tries to load shapekey action into Action Editor (context there is ob-action only). 

There are still a few minor update bugs that I still need to fix here (i.e. post keyframing) though. Those shouldn't take too long I think.

* Changing the action used in the Action Editor properly decrements the user counts now. This solves the bug where you could get actions with a high usercount, but not that many actual users.

release/scripts/ui/space_dopesheet.py

@@ -100,7 +100,7 @@ class DOPESHEET_HT_header(bpy.types.Header):
         if st.mode == 'DOPESHEET':
             dopesheet_filter(layout, context)
 
-        elif st.mode == 'ACTION':
+        elif st.mode in ('ACTION','SHAPEKEY'):
             layout.template_ID(st, "action", new="action.new")
 
         if st.mode != 'GPENCIL':