[PATCH 0 of 2] Improve hg qrecord / record behavior without extensions

[timeless]

Hg has a great feature where it will tell you what extension you need to enable to get a certain command.

This doesn't work with 'hg qrecord' because it doesn't always advertise.
It pays to advertise.

This patch series improves test coverage and then makes the help for qrecord unconditionally available. You still get some hints about needing mq, but they're in slightly better places.