bug#22471: ert batch should print compile parsable error messages

[Phillip Lord]

Currently, when running in batch, ert prints out messages like so:


Running 24 tests (2016-01-27 09:05:17+0000)
   passed   1/24  buffer-string=
   passed   2/24  buffer=
...
   passed  22/24  sisyphus-test-with-find-file
   passed  23/24  to-string
   passed  24/24  with-temp-buffers

Ran 24 tests, 23 results as expected, 1 unexpected (2016-01-27 09:05:18+0000)

1 unexpected results:
   FAILED  crash-out

It would be nice to add some compilation-mode parsable data to this. So,
something like


   passed   1/24  buffer-string=  (in ./test.sisyphus-test.el:22:)

It would also be nice to add colourisation: red and green for passed and
failed. In the idea world, these could be added as ansi colour codes to
the batch output of ERT. They should work on the command line then also.

More of an RFE than a bug, but it is odd that compilation mode works
with lots and lots of test frameworks, but not Emacs'

Phil