WIP: Use history.perform/replace/pop instead of context.perform

This means
* no more weird saves to localStoage of partially merged graphs
* pop cleanly cancels back to history state before merges happen
  (removed the annotated undo states)

data/core.yaml

@@ -326,12 +326,6 @@ en:
       keep_remote: Use theirs
       restore: Restore
       delete: Leave Deleted
-      annotation:
-        safe: Merged remote changes from server.
-        keep_local: 'Kept local version of {id}.'
-        keep_remote: 'Kept remote version of {id}.'
-        restore: 'Restored local version of {id}.'
-        delete: 'Deleted local version of {id}.'
       download_changes: Download your changes.
       done: "All conflicts resolved!"
       help: |