fixed docs for proofManagerLib.restore

Purge on broken links within the (HTML) documentation. This mostly involves
deleting SEEALSO entries (where documentation doesn't exist) but also fixing a
few links.

Also fixed the anchor links in TheoryIndex.html and idIndex.html. In both
cases there aren't any entries starting with the letter "Y".

make the documentation of proofManagerLib reflect the renaming of BBackup to restore and save_proof to save