phabricator: add commenting to phabsend for new/updated Diffs...
phabricator: add commenting to phabsend for new/updated Diffs
Especially useful when sending updates to existing Revisions so one can specify
the sort of changes e.g. "Address review comments" or "Rebase to tip"
If the diff content hasn't changed then it only needs a metadata update which
doesn't show in the Phabricator updates UI, so don't add a comment that will.
Differential Revision:
https://phab.mercurial-scm.org/D6496
