Merge branch 'jc/describe'

Merge branch 'jc/describe'

The "--match=<pattern>" option of "git describe", when used with
"--all" to allow refs that are not annotated tags to be used as a
base of description, did not restrict the output from the command
to those that match the given pattern.

We may want to have a looser matching that does not restrict to tags,
but that can be done as a follow-up topic; this step is purely a bugfix.

* jc/describe:
  describe: --match=<pattern> must limit the refs even when used with --all