Views 1.7 pre-req #1: Write custom taxonomy form

From http://www.angrydonuts.com/anyone-want-to-write-a-couple-of-views-1-patches

Views is trying to re-use taxonomy_form, and unfortunately embeds the entire form into the views data. This is incredibly bad and wrong. It needs to not re-use taxonomy_form so that it can use a callback to fetch a list of possible terms (or use the autocomplete field, as appropriate).

I believe this is referring to a patch that was added in #115856: reuse taxonomy forms (autocomplete) in modules/views_taxonomy.inc.