iterator over strings (aka chunks).
Also added to util (for future use) is a generator function that
iterates over a file n bytes at a time.
Lastly, localrepo was changed to use this new chunkbuffer class when
reading changegroups form the local repository.
- delete copy information when we update dirstate
hg was keeping the copy state and marking things as copied on
multiple commits
- files that are renamed should have no parents
if you do a rename/copy to an existing file, it should not be marked
as descending from its previous revisions.
- remove spurious print from filelog.renamed
- add some more copy tests
- create new statichttprepo class
- pull remote bits out of localrepo
- pull remote bits out of util.opener
- switch hg.repository to use statichttprepo
