zsh completion: add new option groups for options
Add clone, date/user, git-style, merge tool, ignore space, log,
branch/bookmarks options and use them throughout command completions.
$ "$TESTDIR/hghave" pyflakes || exit 80
$ cd "`dirname "$TESTDIR"`"
$ pyflakes mercurial hgext 2>&1 | "$TESTDIR/filterpyflakes.py"
hgext/inotify/linux/__init__.py:*: 'from _inotify import *' used; unable to detect undefined names (glob)