grafx - Extensible Java Graphics Package Code

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.

Adding overallHeightMetric().

Linear scaling of coveredHoleMetric() is extremely important. We want to
continue playing well even if we had the misfortune of already having some
holes in our pit.

Fixing heightMetric(). The rest of the metrics need the same sort of analysis,
after which a suitable linear combination of the metrics should be decided
upon.

Tidy up the code a little bit.

Fixing nook and cranny metric, using square. May even try cube of height
delta if this is not good enough.