tests/test-check-interfaces.py.out

lfs: infer the blob store URL from an explicit pull source

I don't see any easier way to do this because the update part of `hg pull -u`
happens outside exchange.pull(), and commands.postincoming() doesn't take a
path.  So (ab)use the mechanism used by subrepos to redirect where subrepos are
pulled from when an explicit path is given.  As a bonus, this should allow lfs
blobs to be pulled into a subrepo when it is checked out.

An explicit push path can be handled within exchange.push().  That can be done
next, outside of this dirty hack.

public attribute not declared in interfaces: badpeer.badattribute
public attribute not declared in interfaces: badpeer.badmethod