grafx - Extensible Java Graphics Package Code

Adding data/level17-computer.blo. Was a good demonstration.

Now waiting for all user movement events to finish before dropping block.

Making use of the caching strategy for next block orientations. In testing
this barely had an effect on performance.

Starting to optimize getNBestMoves(). Not calling into the optimized version,
yet.

Tidying up some loose ends:
- In BlockPlacementStrategy choosing one of the rotations at random.
- In BlockGenerator adding some main() code which prints out information on
unique orientations of an input block.

Making major changes to BlockGenerator which still outputs the same Blocks.java
file. Moving from Vector to ArrayList, from Hashtable to Hashmap. For all
unique orientations of a block that are computed, listing all composite
rotations to get there.

Adding a comment which begins to describe the desired nature of translations +
rotations.

Changed section inside commented out block, related to testing 2x2x9 pit.

Adding long comment following coveredHoleMetric(), which explain deficiencies
in covered hole metric and explains the difficulty of computing a maximally bad
score. Also adjusting computed value averageEdgesCornersHoleFactor, making it
more accurate especially for small footprint wells such as 2x2.

Making level 23 really really freaking hard.