* REMOVE bridgedb.Bridges module.
 * ADD bridgedb.hashring module.
 * ADD bridgedb.test.test_hashring test suite for bridgedb.hashring.
 * ADD bridgedb.bridges.AdaptedBridge interface adapter (and globally register
   it), for adapting bridgedb.bridges.Bridge to conform to the
   bridgedb.interfaces.IName interface (in order to generalise the constraints
   required for items whose "identity" are HMAC-able, and thus generalising
   which types of items may be inserted into a bridgedb.hashring.Hashring.)
 * ADD adapter registration for some types of mocked Bridges used in
   unittests.
 * FIXES #12505: https://bugs.torproject.org/12505
 * FIXES part of #12029: https://bugs.torproject.org/12029