tests/test-mq-qsave.t

localrepo: make _applyrequirements more specific

Localrepo's _applyrequirements function isn't very straightforward about what
it does. Its purpose is to both act as a setter for the requirements attribute,
and to apply appropriate requirements to the opener's configuration.

This change makes the function just focus on the latter responsibility. We
rename it as such, and make setting the requirements attribute the
responsibility of the caller.

  $ 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