[MERGE][0.19] change the pack interface to use tuples for names

[Robert Collins]

As my NEWS item describes, this allows packs to use tuples for names,
which makes it simple to use composite keys such as ('foo', 'bar') or
('t', FILEID, REVISIONID).

This is wire compatible with packs in 0.18 - as packs are just a
container, writers and readers have to match anyway, but a writer using
a single-string name will generate the same bytes on the wire.

-Rob
-- 
GPG key available at: <http://www.robertcollins.net/keys.txt>.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: pack-tuple-names.patch
Type: text/x-patch
Size: 14172 bytes
Desc: not available
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20070808/7ed7ff72/attachment-0001.bin 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: This is a digitally signed message part
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20070808/7ed7ff72/attachment-0001.pgp