grafx - Extensible Java Graphics Package Code

Carrying over the additional scoreMultiplier field to NightmareModeLevel.

Adding scoreMultiplier field to Level.

Adding a block of code to NightmareModeAction that will record a game to file.
This code block should be moved to a higher level because we need to insert
something in the info string, namely the score multiplier.

Nearing completion on LaunchNightmareLevelPlayback.

Adding beginnings of LaunchNightmareLevelPlayback. Not done yet.

Fixing the FloatPolyClipper with a boundary condition which would lead to
NullPointerException. It seems like a harmless change but it has a huge
impact in very specific cases. This change had already been made to blockout
project, and is tested. Just rolling the fix into this repo. Some benign
comment changes, and benign debug method additions as well.

Adding a comment to BlockGenerator.

Fixing net.blockout.meta.BlockGenerator to name the 1-unit block "O" instead of
"_", the previous name was causing a compile error. It used to work with
Java 1.0, Java 1.1, even with Java 1.2, but apparently not anymore. This
generator now creates a carbon copy of the source file for
net.blockout.production.Blocks, so that source does not need to be adjusted.
It was already adjusted by hand a while back.

Adding a new constructor to PlaybackCanvas which takes a NextBlockListener.

Adding TODO comment to SynchronizedModeGamePlayback.