grafx - Extensible Java Graphics Package Code

Adding AlternateNoChildLeftBehindMetric.

I did something to NoChildLeftBehindMetric which makes it work very well.
Saving work before I lose these changes. Still studying this problem. If code
is reverted, then this commit should be looked at.

In NoChildLeftBehindMetric, leaving comments which indicate how we want the
metric to behave in certain cases.

Adding NoChildLeftBehindMetric.

Adding UpperLeftSectionLowerMetric.

Fixing spelling mistake in comment.

Adding PlugTheHoleMetric.

Adding SquaredHeightMetric.

Adding QuadraticBowlMetric.

Removing a println().