Fix issue #67 - malfunction caused by RCS branches rooted at revision 1.0.
* cvs2svn (branch_tag, vendor_tag): Rename these regexps to the more
appropriate names cvs_branch_tag, and rcs_branch_tag, and modify their
definitions, including introducing some match groups.
(CollectData.add_cvs_branch): Remove.
(CollectData.define_tag): Use the new names for the regular expressions,
and use the match groups to trivially avoid the need for add_cvs_branch().
git-svn-id: http://cvs2svn.tigris.org/svn/cvs2svn/trunk@1759 be7e6eca-30d4-0310-a8e5-ac0d63af7087