When in separate remote mode (via -r <remote>) we can now use
the name HEAD for the CVS HEAD. In keeping with git-clone
remotes/<remote>/HEAD is creates as a symbolic ref to the user
specified name for the HEAD which defaults to master.
Signed-off-by: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>