install django-taggit
move jquery-ui to core verdantadmin js
add tag manager to images
use jquery tag-it on tag fields
suppress default help text on tags, because jquery.tagit means it's not visibly a comma-separated list any more
implement tag autocompletion
update jquery-ui and add a theme so that the autocomplete stuff works sensibly
add tag-it treatment to the tags field in the upload form within the image chooser
Merge branch 'tagging'