grafx - Extensible Java Graphics Package Code

Level 29, 12 layers to clear, not 11.

Implementing a "minimalist mode" in GameSidebar, which just removes the high
score display.

Giving the modern AudioClipStore treatment to LaunchLevelPlayback, so that we
would not need to list every bg music clip in the code.

Increasing difficulty of level 29. Not sure about level 30... remove it? I
don't know which one is harder at this point.

Giving the new AudioClipStore treatment to LaunchComputerPlayerRetry.

Using the new AudioClipStore functionality of having a 'fallback' source for
audio clips, in LaunchComputerPlayerTest. This is so that any of the bg music
clips could be loaded, w/o listing them all in code.

Adding a new key, KEY_MINIMALIST_SIDEBAR = "minimalistSidebar".

Adding 'fallback' option to AudioClipStore. This is so that background music
can be dynamically loaded from filesystem, w/o the need to explicity list every
background music audio clip in the code.

Now copying all looping WAV files, not just one.

Adding info about the new clip to README.