tests/test-purge-ignored-directory.t

typing: add some trivial type hints to `mercurial/match.py`

These were new methods since hg 3dbc7b1ecaba, but surprisingly pytype couldn't
figure them out.

skip ignored directories if -i or --all not specified

  $ hg init t
  $ cd t
  $ echo 'ignored' > .hgignore
  $ hg ci -qA -m init -d'2 0'
  $ mkdir ignored
  $ ls
  ignored
  $ hg purge -v --no-confirm
  $ ls
  ignored