grafx - Extensible Java Graphics Package Code

Changing level twenty-three from 7x5 to 6x5.

Changing location of code entry function and fixing an error, needed to clear
HashSet before every call (or after every call).

Embellishing comments in WellMetricUtils.

In CoveredHoleMetric, removing toUncoverHoleIsFilledCubeOnTopHelping() and all
comments therein.

One more little optimization plus a comment improvement in CoveredHoleMetric.

Defining m_holeCountsByLayer in CoveredHoleMetric. Saving that object as
member to avoid excessive instantiations.

In the process of optimizing CoveredHoleMetric. Keeping objects
m_sqrtEdgesCornersWeightsCache and m_coveredHoles as members instead of
instantiating every time.

Comment formatting in AlternateNoChildLeftBehindMetric.

Optimizing QuadraticBowlMetric by caching elevations.

Optimizing LinearBowlMetric by caching elevations.