adding todos
adding notes around explicit prepare problem, and a few todos
beginning work on explicit prepare phase
adding links to the egalitarian paxos papers
starting on the sendPrepare... need to add support for getting replicas for a key first
adding clusterproto library
fixing sendPrepare
adding get nodes method to mock cluster
removing old interface
adding methods for getting replicas for a scope/consistency level
removing consistency level awareness from consensus for now
adding some stubbed management tests
removing unused import