[horde] API to Registry $_interfaces

[Chuck Hagenbuch]

Quoting Steve Ivy <steve at contentconnections.com>:

> I note that the Registry has an $_interfaces array, but it seems to be
> unused in the API. We're looking to be able to query Horde for "what
> app provides the 'foo' interface?" - has anyone else touched on this
> and have any ideas?

Try what I just committed:
http://cvs.horde.org/diff.php/framework/Horde/Horde/Registry.php?r1=1.222&r2=1.223&ty=h

-chuck

-- 
"But she goes not abroad in search of monsters to destroy." - John 
Quincy Adams