[#1979000]: Ported issue tag support to D7
- Injected a setting on vocabulary forms to select if the vocab should
be used for the issue queues (and if so, what widget to use for the
exposed filters).
- Ported _project_issue_views_add_taxonomy_filters() to D7 and we use
it to build the advanced search default views instead of the bogus
taxonomy_vocabulary_9_tid filter that was hard-coded.
- Alter in a new term URI callback to the term entity that checks if
the term is from an issue queue-enabled vocab. If so, link to the
site-wide advanced search, else fallback to taxonomy_term_uri().