grafx - Extensible Java Graphics Package Code

Making minor tweaks to the weights on the metric functions. Plays very well.

Cleaning up the comments a bit in coveredHoleMetric(). I was not able to come
up with a more intelligent upper bound on the worst score.

Adding some comments.

Caching the sqrtEdgesCornersWeight() factors on <x,y> grid.

Adding comments describing exactness of worst score computation for nook and
cranny metrics.

Backing out the corner/edge logic in "plug the hole" metric. It did not have a
desirable effect.

Modifying "plug the hole" metric, making holes near corners more disagreeable.

Renaming NOOK_AND_CRANNY_METRIC to LINEAR_NOOK_AND_CRANNY_METRIC.
Renaming BOWL_METRIC to LINEAR_BOWL_METRIC.
Defining LINEAR_NOOK_AND_CRANNY_METRIC and QUADRATIC_BOWL_METRIC, both of which
are currently set to zero.

Better way of defining levels, not in array.

Increasing qSearchBreadth.