Cleanup of core file, removing relics of prior ways of doing things
Testing of the utilities found in core
Reshaping standard array from (depth, height, width) to (height, width, depth)

Two major benefits:
* Makes updates in bressenham simpler
* Makes colors conceptually a list of r/g/b/a category values

As downside, its harder to read output or write test.  The standard solution is to do a transpose so the visible output is always (depth, height, width).
Fixes for lines (and more tests)