[MERGE] Support streaming push to stacked branches.

[Robert Collins]

This completes the addition of the RPC verb `Repository.insert_stream`,
allowing streaming push to RemoteRepository objects which are stacked.

With this we're down to 60 round trips for push of a trivial branch, and
85 for a stacked trivial branch.

-Rob

-------------- next part --------------
A non-text attachment was scrubbed...
Name: fetch-RemoteSink-4030.patch
Type: text/x-patch
Size: 21588 bytes
Desc: not available
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20090223/4d6150c2/attachment-0001.bin 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 197 bytes
Desc: This is a digitally signed message part
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20090223/4d6150c2/attachment-0001.pgp