tags: deprecated 'repo.tag'

All user are gone. We can now celebrate the removal of some extra line from the
'localrepo' class.

mercurial/localrepo.py

@@ -650,6 +650,7 b' class localrepository(object):'
         return hook.hook(self.ui, self, name, throw, **args)
 
     def tag(self, names, node, message, local, user, date, editor=False):
+        self.ui.deprecwarn("use 'tagsmod.tag' instead of 'repo.tag'", '4.2')
         tagsmod.tag(self, names, node, message, local, user, date,
                     editor=editor)