first semi-working marching cubes version!

seems to create only one side of the surface.  only active for
uint16 data right now.  other issues, i'm sure.
Edge table doesn't need to be a class variable.

&& we don't need a copy of it per-type.
fix line endings.
triTable also doesn't need to be typed.
Fix indentation.  Change triTable to int16_t.

I had somehow broken the indentation along the way?
edgeTable can be an int16_t, as well.
Support multiple types as input data for MC.