Added: Multithreaded the ErrorSim. Also changed its name to ErrorSim.
Transfered all functions from ErrorSim to it's sub components. ErrorSim
invokes a ListenerESim thread about startup. Files for subsystems of
ErrorSim are ListenerESim.java and ConnectionManagerESim.java.
Added: ErrorSim.java, ListenerESim.java, ConnectionManagerESim.java.
Changed server code to spawn new listener thread. Removed extraction of
message from Listener.java, as this was not needed for any reason.

Fixes: Remove Addition of diff files to repository