cvsserver: remove unused functions _headrev and gethistory
cvsserver: remove unused functions _headrev and gethistory

Remove:
   - _headrev() - It uses similar functionality from getmeta() and gethead().
   - gethistory() - It uses similar functions gethistorydense() and getlog().

Signed-off-by: Matthew Ogilvie <61d305474f7b62eea2525639840df42d3605ddd6@miniinfo.net>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git