[MERGE] Add optional 'fetch_spec' to argument to Repository.fetch

[Robert Collins]

Robert Collins has voted tweak.
Status is now: Conditionally approved
Comment:
remove the knit XXX: its not going to be found there :)
MiniSearchResult needs a couple of nominal tests.
Please add to the docstring of Repository.fetch that fetch_spec can 
handle multiple heads.
We need a test_smart test for using MiniSearchResult I feel.
I'd like to suggest deprecating revision_id, but I think that needs a 
[more] complex search result to be able to pass in, so we should wait.
Perhaps MiniSearchResult could take a list of revs rather than just one, 
as a heads-list.
Also, perhaps MiniSearchResult should be a PendingAncestryOfResult ? (Or 
similar name; Mini is just too vague/contextual.

For details, see: 
http://bundlebuggy.aaronbentley.com/project/bzr/request/%3C20090306005950.GD7819%40steerpike.home.puzzling.org%3E
Project: Bazaar