zsh_completion: adjust usage of common options
addremove, remove and serve accept -S/--subrepos, and purge actually doesn't.
qnew accepts -I/--include and -X/--exclude.
qrefresh accepts -D/--currentdate, -U/--currentuser, -d/--date and -u/--user.
rebase accepts -n/--dry-run.
Differential Revision: https://phab.mercurial-scm.org/D4360
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)