Bug XXX - Factor superclass ServerRepository out of subclass Server11Repository; create subclass Server20Repository.
Bug XXX - Move non-Sync specific PUT and POST methods to BaseResource.
Bug XXX - Create Server20Client for testing protocol 2.0 servers.
Bug XXX - Factor superclass ServerRepositorySession out from subclass Server11RepositorySession.
Bug XXX - fix
Bug XXX - fix TestServer20Client.
Bug XXX - Correct whitespace in SyncServer11Response.java.
Bug XXX - wip on server20RepositorySession.