Removed some javadoc parts that no longer make sense.
Added some optimizations for zero angles.
Removed some old code.
Turned AffineTransform's zero-argument ctor into a static method.

Also:
- Renamed an argument to match the according Matrix static method's argument.
- Added some ore javadocs and
- Reordered some arguments to fit the flow of those javadocs
Made Matrix3's ctors private.