Reduce callback_manpage() duplication between SVNRunOptions and GitRunOptions.
Patch by: Greg Ward <greg@gerg.ca>
* cvs2svn_lib/run_options.py: Add RunOptions.write_manpage().
* cvs2svn_lib/man_writer.py: ManWriter: Turn most constructor args
into optional keyword args for convenience of
RunOptions.write_manpage().
* cvs2svn_lib/git_run_options.py,
cvs2svn_lib/bzr_run_options.py,
cvs2svn_lib/svn_run_options.py: Shrink callback_manpage() a bit by
calling write_manpage().
git-svn-id: http://cvs2svn.tigris.org/svn/cvs2svn/trunk@4908 be7e6eca-30d4-0310-a8e5-ac0d63af7087