After a tag has been "edited" and renamed such that it is merged with another tag, I would guess the expected behavior is that eliminated tag should no longer appear in the autocompletion list. However, that appears to case.
To reproduce:
-Add two tags and add it to some items.
-"edit" one of the tags, rename it the second tag.
-Create or edit an item and go to the tag section. Now, start typing the name of the tag that was eliminated, note that it continues to appear.
I assume that the edited-eliminated tags are not actually removed from the database table listing all previous tags.

