1) Generate the form in Tags_Controller::_form_add()
2) Process the form submit in Tags_Controller::_create()
3) Create the tag properly
This required me to limit our scope to adding one tag at a time, which
I think is fine if we're doing Ajax style tag addition.
1) change buckets to be 1-7 not 0-6.. zero-based indicies don't make sense in the
real world and are liable to confuse themers.
2) Change tag API to popular_tags($count) which just returns the popular tags. Let
the block code massage it into the right format for the view.
3) Move alphasort into the block code, simplify it and rename it to sort_by_name so
that it's more descriptive
4) Do the bucketing in the view; this allows the themer to override it and create their
own bucketing algorithm to go with the theme's CSS.
5) Don't create any temporary objects.
