Fixing Java warnings by closing Closables
Refactoring Driver.java
Refactoring NewGameMenu (renamed to NewGamePanel)
Renaming GUI classes to better reflect their types
Removing unneeded instance variables from PlayGamePanel and PlayNetGamePanel
Renaming instance variables to match the new convention
Finish renaming GUIUtility to GuiUtility. Issue #107
Replace AbstractWindowListener with AWT's WindowAdapter. Issue #108.
Merge pull request #109 from tsmacdonald/master

Refactor/fix changes introduced in commit ad88c