KVClient
    - Removed 2PC put/del methods
    - Removed get with timeout
    - Removed all mentions of the status field

TPCMaster
    - SlaveInfo now only has hostname and port, the KVClient and Socket references have been taken out.
    - Added connectHost and closeHost methods
    - performTPCOperation no longer has a return status

KVMessage
    - Now implements the Serializable interface.
    - Added a sendMessage method with a timeout.
Adding a hasKey method to KVServer
Added a constructor for KVMessage with a timeout

Added RegistrationHandler class in TPCMaster