grafx - Extensible Java Graphics Package Code

Adding the capability of playing background music during game playback. The
BLO file header determines which music to play.

Adding some infrastructure for playing background audio during playback.

In BLO file header writer "embedding" background music string. Computer player
sets this. We need this for playback, somehow. How do we know if the game was
played by computer? Don't want background music for human game, only computer,
etc.

Now supporting '--noaudio' flag in launch-retry.sh.

Adding the rocketman.wav background music in launch-retry.sh.

Adding nightmare level #8.

Adding a couple of TODO comments.

We should study this game. The computer logic seems to be off.

Implementing '--noaudio' command-line flag in launch-playback.sh script.

Adding nightmare-hi-score.blo.