grafx - Extensible Java Graphics Package Code

Streamlining the clearing of layers in BlockPlacementStrategy. This should
speed up the decision-making for best move even more.

Caching the return value of getBestCanonicalRotation().

Now that BlockPlacementStrategy has been optimized and now that it runs more
quickly, increasing qSearchBreadth in ComputerPlayerLevelAction from 16 to 20.

Making level 29 a wee bit harder.

All comment and error message changes, in BlockPlacementStrategy. The
proofreading with a fine-toothed comb is nearing an end. I will likely test
extensively with various levels, but I also want to redo the order in which
xOff and yOff are set, to start from center and move towards outside.

Comment and style changes.

Adding a little bit of a Javadoc comment to BlockPlacementStrategy.

Removing unused import statement for HalfPosition.

Making massive changes to BlockPlacementStrategy, finally. Still need to do a
major proofread, esp. in function getNBestMovesFin(). Major changes on
priority of post drop slide moves.

In net.blockout.meta.BlockGenerator, making getBlockName(Layer[]) public since
that does not depend on center of block rotation. Also adding a new function,
getBestCanonicalRotation(), and adding necessary code to support it.