grafx - Extensible Java Graphics Package Code

Optimizing OverallHeightMetric a bit. Compared output values to those of old
function and they match.

Optimizing SquaredHeightMetric a bit. Tested to make sure that output values
match those of previous function.

Increasing qSearchBreadth back to 24. Went 32 -> 16 -> 24. Good number.

Optimizing WellMetricUtils a tiny amount.

Adding line of commented out code. The old call to coveredHoleMetric().

Making some fairly simple, straightforward optimizations to the code. Just
trying to squeeze out a tiny bit of better performance; this will hardly make a
difference actually.

Changing level twenty three from 6x5 pit to 7x5. A tad easier.

Adding stuff to TODO.txt.

Making level 23 much harder by reducing the pit size. Now it has no problem
passing this, with the improved covered hole metric. 7x6 -> 6x5.

Changing qSearchBreadth from 32 to 16. I think I may need to optimize the new
CoveredHoleMetric a little bit.