log -v failure related to lazy imports

[Matthew D. Fuller]

With current bzr.dev, "log -v" in any tree falls apart with:

bzr: ERROR: exceptions.ImportError: cannot import name RevisionTree

If I back up to rev 2070, it works.  2071 ("use lazy importing to
improve startup time") falls apart.


-- 
Matthew Fuller     (MF4839)   |  fullermd at over-yonder.net
Systems/Network Administrator |  http://www.over-yonder.net/~fullermd/
           On the Internet, nobody can hear you scream.