More RBC cleanup.

Remove extra .good and .prediff, and update comment.
Add MatrixHelpers module with transpose and dotProduct procs.

These are specific to 2D arrays of reals. Tests are included.
Add RBCElegant, which uses dotProduct and transpose function.

This makes the top of the while loop look a lot nicer, but as expected it
causes a significant performance decrease. This is due to allocating a new
domain and arrary each time those functions are called.

RBCElegant has comparable performance to the Python with Numpy version on my
mac.