add pretag and tag hooks.
pretag hook lets hook decide how tags can be named. tag hook is
notifier.
Metadata-Version: 1.0
Name: mercurial
Version: 0.7
Summary: scalable distributed SCM
Home-page: http://selenic.com/mercurial
Author: Matt Mackall
Author-email: mpm@selenic.com
License: GNU GPL
Description: UNKNOWN
Platform: UNKNOWN