This removes all calls to inAnnex, except for some involving --batch.
It may be that the batch code could get a similar speedup, but I don't
know if people habitually pass a huge number of files through --batch
that git-annex does not need to do anything to process, so I skipped it
for now.
A few calls to ifAnnexed remain, and might be worth doing more to
convert. In particular, Command.Sync has one that would probably speed
it up by a good amount.
(also removed some dead code from Command.Lock)