WorkerThread refactored

WorkerThread rename BotThread

WorkerThread, now BotThread has been refactored, all calls to this.sleep(x);
has been replaced by a sleepThread(x); method. This new method relies on timers
 to temporarily pause the thread.
Solves bug: GUI freezes during workerThread sleep

BotThread now extends SwingWorker rather than thread.

newBot method added in GUI, instantiates the BotThread bot object.