grafx - Extensible Java Graphics Package Code

Making some progress on the fancier line drawing routine (3D). Updated some
test code previously; committing those as well.

Adding line clipper which does clipping of interpolated line colors.

Re-adding the drawLine() with color interpolation. We're going to do this.

Improving the performance of line drawing algorithm.

Finished LineRotate.

Starting new test class, LineRotate.

Changing order of some boolean && or || to make it more symmetric, readable.

Finished with the line drawing subroutines.

Adding one more of the line drawing subroutines. Seems to work.

Fixing a wrong increment for 'dd'.