grafx - Extensible Java Graphics Package Code

Changing version, 2.3.1 --> 2.3.2, in webpage.

Updating grafx-2.3-RELNOTES.txt.

Fixing a compile error in 3D rendering library. This change is just to get it
to compile; there will be major work done to the 3D code soon. The change in
question is related to getPointAlias(), the public method.

Changes for 2.3.1 -> 2.3.2, 2D grafx rendering library.

Now testing with Double.isNaN() in ClipRectangle.

Adding clipRectTests() to NaNTest.

Discarding polygons with Double.isNaN().

In RasterFloatGraphics, breaking the FloatPolyEdge.initialize() calls into
separate loop, for clarity and for debugging purposes. Of course there is a
very slight performance penalty to be paid with this change.

In NaNTest adding some additional test cases for fillPolygon().

In FloatPolyEdge, moving numNodes() to the bottom of file (it's a debugging
call), making incrementY() private (was protected, I don't know why), and
adding printNodes() for debugging purposes.