Warn on old CF names in searches

Warn on startup and when searching if old CF names with
the _RTIR_ prefix or State are found in queries or formats.
Include the user/search information in the warning.

Borrow the location argument to say "This search was ad-hoc by Bob" or
"This was RT::User-12-SavedSearch-40 executed by Alice" which gives
admins enough rope to find and fix the problematic searches.
Merge branch '2.9/warn-on-old-search-formats' into 2.9-trunk