tests/test-revert-flags.t

cmdserver: mask return code of runcommand in the same way as dispatch.run

"hg help" does not state that the code for abort is 255, but it's confusing
to have different code between hg command and command server.

Tests of python-hglib 1.2 passed with this change.

  $ "$TESTDIR/hghave" execbit || exit 80

  $ 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 ..