test-lfs: add tests covering local exchanges
The root issue here is that requirements are not exchanged and preserved on
push/pull. This can be handled with a changegroup hook. Testing for remote
exchanges is much more extensive (it's possible for one process or the other to
not have the extension loaded at all), so it is added separately.
Test issue2761
$ hg init
$ touch to-be-deleted
$ hg add
adding to-be-deleted
$ hg ci -m first
$ echo a > to-be-deleted
$ hg ci -m second
$ rm to-be-deleted
$ hg diff -r 0
Same issue, different code path
$ hg up -C
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ touch does-not-exist-in-1
$ hg add
adding does-not-exist-in-1
$ hg ci -m third
$ rm does-not-exist-in-1
$ hg diff -r 1