tests/test-diff-newlines.t

mq: use ui.allowemptycommit to allow empty commits

Previously, mq used the force flag to allow empty commits. Now that we have
ui.allowemptycommit let's switch to that instead. We can't completely remove the
force flag since it is used for a bunch of other behavior in localrepo.commit.

  $ hg init

  $ $PYTHON -c 'file("a", "wb").write("confuse str.splitlines\nembedded\rnewline\n")'
  $ hg ci -Ama -d '1 0'
  adding a

  $ echo clean diff >> a
  $ hg ci -mb -d '2 0'

  $ hg diff -r0 -r1
  diff -r 107ba6f817b5 -r 310ce7989cdc a
  --- a/a	Thu Jan 01 00:00:01 1970 +0000
  +++ b/a	Thu Jan 01 00:00:02 1970 +0000
  @@ -1,2 +1,3 @@
   confuse str.splitlines
   embedded\r (no-eol) (esc)
  newline
  +clean diff