tests/test-revert-flags.t

phabricator: fix a phabsend crash when processing a renamed binary

This was a trivial fix, and some more tests are added to cover binary files.
Since the old filecontext is passed in, the old name is still available.  But I
noticed some weirdness around what it marked as binary and not, and what is
viewable in Phabricator.  Those things have been flagged, and will probably take
some digging.

Differential Revision: https://phab.mercurial-scm.org/D8133

#require execbit

  $ hg init repo
  $ cd repo
  $ echo foo > foo
  $ chmod 644 foo
  $ hg ci -qAm '644'

  $ chmod 755 foo
  $ hg ci -qAm '755'

reverting to rev 0

  $ hg revert -a -r 0
  reverting foo
  $ hg st
  M foo
  $ hg diff --git
  diff --git a/foo b/foo
  old mode 100755
  new mode 100644

  $ cd ..