Merged 5 classes, started to implement DatabaseConnector methods and
moved the PollingThread from CommunicationManager into ClientManager.
Changed the type of state column in client_jobs table from VARCHAR to
TINYINT (java byte) and change this variables to bytes in StatePacket
and PacketFacotry.
Changed ClienFile to contain both clientID and job ID. 
Made RequestManager queue ClientFile objects instead of only MainPackets
(JobThread need to know both the clientID and jobID).