grafx - Extensible Java Graphics Package Code

Adding comment for plugTheHoleMetric(). This needs some very careful
consideration.

Beginning to work on plugTheHoleMetric().

Adding scripts/launch-hard-level-test.sh.

Adding missing println() for metrics.

Tweaking the linear combination of metrics. Performs well.

Fixing computation of meanAltitude in heightFluctuationMetric().

Having old and new covered hole metrics.

Adding heightFluctuationMetric().

More intelligent weighted average code.

Renaming heightMetric() to oldHeightMetric(). Want to preserve this code as
well as the comment because the comment had insights.