TUC-2059
TUC-2137
Updated quorum determination logic to only use active witnesses if there are not enough DB members to comprise a quorum.  Also added quite a few unit tests to validate that the logic works correctly.

For TUC-2137, added a new rule that looks at the DataServerNotification for slaves/relays and if read_only=OFF, turns it on....


git-svn-id: http://tungsten-replicator.googlecode.com/svn/trunk@2564 9f5e3340-5c9a-25cb-7c1c-c133a2e9e928