[MERGE] Use a LRUCache in LocalTransport.clone

[John Arbash Meinel]

John Arbash Meinel has voted comment.
Status is now: Semi-approved
Comment:
I'm okay with adding a cache if we need it, but this really does seem to 
be just a mask over the real issue.

I'm pretty sure we don't need to call clone() because Repository should 
already have a transport pointing at .bzr/repository.

I don't actually see where in "get_weave_or_empty()" we are ending up 
with a Transport.clone(). VersionedFileStore already has a 
self._transport which it passes in to 
self._versioned_file_class(filename, self._transport, ...)

So I would prefer if we track down the odd behavior, rather than 
covering it up with a cache.


For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C20080104144118.GU8365%40steerpike.home.puzzling.org%3E