grafx - Extensible Java Graphics Package Code

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.

Adding NightmareLevelPlayback. Still working on it.

Adding DummyUserInput.

Showing how to use NextBlockListener with the playback.

Making a first pass at the NewBlockStartsEvent logic. It's complete but
untested.

Making incremental progress towards the NextBlockListener logic in
SynchronizedModeGamePlayback.

Spiffy up SynchronizedModeGamePlayback a little bit, getting ready for reading
new block starts events for NextBlockListener.