Don't unconditionally overwrite all the proc's description, author
etc. Instead, try to preserve them and append the "Deprecated" notes
to the help texts and generated comments.
Only affects one procedure because we killed the meta info of all
other deprecated procs so far, but now we don't have to do that any
longer.
It never belonged inside "tools". Also rename its "pdb" subdirectory
to "groups". This had to happen before 2.10 so cherry-picking between
branches doesn't become a nightmare in the future.
