grafx - Extensible Java Graphics Package Code

Adding external class StatsUpdater, but it isn't being used yet. I should
proofread this code again. Not even tested yet.

Adding interfaces CubeStats, LevelStats, & NightmareStats, and having
GameSidebar implement them.

Modifying NightmareLevelTest to use external ScoreReporter class.

Updating ComputerPlayerTest to use external class ScoreReporter.

In LevelTest, using ScoreReporter that is in a separate class file now.

Speeding the block moves back up from 210 millis to 200. It was too slow.

Making use of new ScoreReporter class. The changes should have no impact of
order of underlying calls, esp. to setScore() and setHighScore(). These are
minimally intrusive changes which make use of Score Reporter. Also now the
current score and high score pointers are exposed, as privte, in member vars.

Adding class net.blockout.production.ScoreReporter. Not using it yet.

Moving HighScoreDisplay to GameScoreDisplay, which is now an interface, and
having GameSidebar implement that. I'm in the process of refactoring some
code.

Taking care of some very minor odds and ends; improving Javadoc and removing an
import statement that was not used in LevelPlayback.