phabricator: allow local revisions to be specified with `phabupdate` It's way easier and less error prone to specify a revset after importing a series than to manually type in a series of Differentials. Unlike most revision oriented commands, this requires the `--rev` option explicitly because the existing `DREVSPEC` doesn't need to have the leading 'D', and therefore the meaning is ambiguous. I wouldn't have a problem giving precedence to the local revnum, but `phabread` and `phabimport` also use DREVSPEC, and local revisions make no sense there. I would be fine with modifying that definition to require the leading 'D', but I'm not sure how many people are used to not specifying it. Differential Revision: https://phab.mercurial-scm.org/D9356