[MERGE] Use registry for revision specifiers

[Jelmer Vernooij]

The attached patch changes the revision specifiers to use a registry
rather than a list of items. This allows lazy registration of revision
specifiers, such as "svn:". 

Revision specifiers and control formats are the only two things that
can't be lazily registered yet and that trigger loading of more than
just bzrlib.plugins.svn.__init__ when running (non-svn) bzr operations
and bzr-svn is installed.

Cheers,

Jelmer
-- 
Jelmer Vernooij <jelmer at samba.org> - http://samba.org/~jelmer/
Jabber: jelmer at jabber.fsfe.org
-------------- next part --------------
A non-text attachment was scrubbed...
Name: revspec-registry.diff
Type: text/x-patch
Size: 7374 bytes
Desc: not available
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20090128/c20d48ef/attachment-0001.bin 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 315 bytes
Desc: This is a digitally signed message part
Url : https://lists.ubuntu.com/archives/bazaar/attachments/20090128/c20d48ef/attachment-0001.pgp