match: handle everything-matching using new alwaysmatcher Having a special matcher that always matches seems to make more sense than making one of the other matchers handle the case. For now, we just use this new matcher when no patterns were provided.

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init

  $ echo 'base' > base
  $ hg ci -Ambase
  adding base

  $ hg qnew -mmqbase mqbase

  $ hg qsave
  $ hg qrestore 2
  restoring status: hg patches saved state