GitLab

* doc/emacs/vc1-xtra.texi (Version Headers): Note that these are for
Subversion, CVS, etc. only.
(General VC Options): De-document vc-keep-workfiles.  Fix RCS-isms.

* doc/emacs/maintaining.texi (Change Log Commands): Don't specially mention
vc-update-change-log which is CVS-only.