* admin.c (admin_fileproc): Undo last commit. TAG_TRUNK test removed.

* commit.c (check_fileproc): Imporve comments. TAG_TRUNK test removed.
(commit_fileproc): TAG_TRUNK test removed.
(remove_file): TAG_TRUNK test removed.
* update.c (update_fileproc): TAG_TRUNK test removed.
* rcs.c: Improve comments.
(RCS_gethead): Remove this fn.
(RCS_getversion): TAG_TRUNK test removed.
(RCS_gettag): Remove magic conversion.
(RCS_nodeisbranch): Properly detect magic for numeric rev.
Remove magic conversion.
(RCS_whatbranch): Gratious reformatting. Simplify.
(translate_tag): Always return non-magic branches for symbolic/extended
tags. Add param flag to prevent conversion for non-extended tags.
Improve assumption verification.
(RCS_extract_tag): Adapt error msg to cvs conventions.
(RCS_getprevious): Rootdate comparison fixed.
(RCS_getroot): Remove magic conversion.
* sanity.sh: More tests added.
(Patch from Frank Hemer <frank@hemer.org>.)