GitLab

* vc/vc.el, vc-hooks.el, and all backends: API simplification;
vc-stay-local-p and repository-hostname are no longer public
methods. Only the CVS and SVN backends used these, and the SVN
support was conditioned out because svn status -v is too slow.
The CVS back end retaiin this machibery and the vc-stay-local
configuration variable now only affects it.