Circular imports break utilities/make-dummy-hosted-branches and 'make run_all'

[Brad Crittenden]

/home/bac/canonical/lp-branches/trunk/bin/py ./utilities/make-dummy-hosted-branches
Traceback (most recent call last):
  File "./utilities/make-dummy-hosted-branches", line 27, in ?
    from lp.code.model.branch import Branch
  File "/home/bac/canonical/lp-branches/trunk/lib/lp/code/model/branch.py", line 49, in ?
    from lp.code.model.branchmergeproposal import (
  File "/home/bac/canonical/lp-branches/trunk/lib/lp/code/model/branchmergeproposal.py", line 47, in ?
    from canonical.launchpad.database.diff import Diff, PreviewDiff, StaticDiff
  File "/home/bac/canonical/lp-branches/trunk/lib/canonical/launchpad/database/__init__.py", line 19, in ?
    from lp.registry.model.product import *
  File "/home/bac/canonical/lp-branches/trunk/lib/lp/registry/model/product.py", line 35, in ?
    from lp.code.model.branch import BranchSet
ImportError: cannot import name BranchSet
make: *** [hosted_branches] Error 1

[Tim Penhey (thumper)]

Fixed in RF 8600.