grafx - Extensible Java Graphics Package Code

Augmenting GameSidebar to support nightmare mode.

Adding LaunchNightmareLevelTest, which right now is essentially a carbon copy
of LaunchLevelTest. Will be making changes incrementally.

NightmareLevelTest is as of right now a carbon copy of LevelTest, modulo the
class name and copyright notice. I will gradually make changes as fit.

Adding a class-level comment to NightmareModeAction.

Adapting TestGameLogic to new "add layers from bottom" framework.

Adding WooHooSND.java.

Starting to add the better framework for adding layers to bottom of pit at
certain time intervals.

Adding AddLayersFromBottomAlgorithm.

Adding suspend()/resume() to NightmareModeAction.

Adding support for block drop speedup in NightmareModeAction.