[MERGE] Add an InventoryEntry cache for xml deserialization

[Ian Clatworthy]

John Arbash Meinel wrote:
> Vincent Ladeuil wrote:
>> Since they are around fast-import using an inventory for its own
>> purposes and apparently being tricked by the cache when trying to
>> handle renames, I'm not sure where the bug should be fixed, but
>> since I saw the test failures, I thought I should at least report
>> them.
> 
>>   Vincent
> 
> 
> So I dug into this, and I've fully determined that bzr-fastimport is at
> fault here.

Thanks. Patch merged to the fast-import trunk now - rev 92.

Ian C.