grafx - Extensible Java Graphics Package Code

New API for getCanonicalBlock2(), which now returns an array of length two,
where each entry in array, if not null, is a canonical representation. This is
likely the hardest problem I've ever worked on, with the symmetries,
recursions, etc.

Changing some variable names. Really an innocent change.

Simplifying getAll_n_Blocks(int).

Starting to improve the correctness in getAll_n_Blocks(int), both in Javadoc
and in the code. Efficiency will be improved as a side effect. Right now the
overall build will be broken for a while.

Slight change in Javadoc comment.

Adding new getCanonicalBlock(), with a different name for now. Not being used
yet. I need to rest a little because this is very complex.

Some change of name, findBestBlock() -> findBestBlockOrientation(), which
returns a BlockOrientation objects intead of a Layer[] object. An inner voice
told me to make this change, I don't know the exact reasons for it [yet].

Adding an item to TODO.txt.

Making very slight incremental progress. This is extremely difficult because
it's highly recursive, there is a chicken and egg problem, and there is a great
deal of reflexivity in code, not just in the block itself. It's almost as if
I'm solving some deep issues in the Universe. I think I know what has to be
done. I think findBestBlock() has to be changed to return a BlockOrientation
object next.

Adding additional comment to findBestBlock() explaining that returned array
will be equal by reference to 'orientedBlock' of one of the input list's items.