grafx - Extensible Java Graphics Package Code

Adding check to constructor of RasterDepthGraphics to ensure that both width
and height are strictly greater than zero.

Adding some Javadoc to RasterDepthGraphics which states that exception is
thrown when unimplemented method is called.

Throwing exception when the unimplemented methods are called on
RasterDepthGraphics.

Adding TestLineOverlap with extremely good results. I cannot find a single
pixel that is off, even after millions of attempts.

Fixing the broken build.

Removing entire package net.blockout.production.hiscore.

Removing 'userpref' directory from net/blockout/production/.

Removing all Tetris-related stuff. I think this is a dumb game, for dumb
people. I find it to be totally bland, boring, and uninteresting. I don't
want to modify my other code just so that it could play this stupid game.

Adding some anal checks & proofreading code in CanvasSplitter. Adjusting one
'while' loop - using 'do ... while' in its place because that is more correct.
Removing TODO comment because the logic is correct, or it seems to be so, after
close examination. The original code was actually fine.

Modifying the formatting in Javadoc comments.