Sending Clusters + Basic Server Thread

ClusterTransmitTools.java:
-Adds a function transmitCluster() that when given a cluster as a
ArrayList, transmits it appropriately to the provided socket or
PrintWriter.
-Sending begins with a START-CLUSTER message and ends with a
END-CLUSTER message.

BasicServerThread.java:
-Can be initialized by providing a ArrayList of Videos and a
Socket to talk with.
-On initially running, it transmits all videos to the socket.