Updated todo.
Made target_generation and target_trans_id optional in GetDocumentResponse message.
Added doc_rev attribute to GetDocumentResponse.
Added sequential send and receive docs in sync_exchange. Incomplet now.
Fixed protobuf tests wrt new changes.
Fixed typo in zmq_target
Added tests for server. A work in progress.
Changed import statement.
Changed tests to check if method was called.
Updated .gitignore
Updated requirements.txt
Changed protobuf message ClientInfo from string to type byte.
Refactored server side for sending received messages from client to the application instead of parsing them.
Wrapped line under 79 chars in zmq_base.
Completed app-server-client communication wrt sync.
Added server_state module from u1db trunk.
Removed queue. Queuing messages directly on the socket itself.
Added sync module from u1db trunk.
Added SyncResource class and reponse methods for handlers to get_sync_info_request and put_sync_info_request.
Merged zmq_app into unittests.