Checkpoint 1 - Hello, UberFire!
Checkpoint 2 - Add a second screen
Checkpoint 3 - Add a menu bar

Conflicts:
	src/main/java/com/mycompany/uftutorial/client/HomePerspective.java
Checkpoint 4 - Add a contextual toolbar
Checkpoint 5 - Add a second perspective
Added logout button (TODO: merge into tutorial docs)