Corrections and HashTable iterator example added.
Added BeatModelInterface.
BeatModel class added.
Additions to BeatModel class.
Added DJView class.
DJView class completed.

NOTE: The rest of this classes code was copy/pasted from www.wickedlysmart.com.
ControllerInterface added.
BeatController class added.
BeatBar class added.

NOTE: It's not in the chapter.
Some additions.
Multithreading example added.
More multithreading examples added.
GuessANumber class added.
ThreadClassDemo added.