[PATCH 2 of 3] phabricator: add phabsend command to send a stack

[Jun Wu]

Excerpts from Phillip Cohen's message of 2017-07-03 13:38:34 -0700:
> > +    """
> > +    revs = list(revs) + opts.get('rev', [])
> > +    revs = scmutil.revrange(repo, revs)
> > +
> 
> I'd add something like this here:
> 
> if not revs:
>     raise error.Abort(_('must specify at least one changeset with -r'))
 
Good point. I'll send a follow up.