add 3d movements; examples cube and bauble
add quat,vec classes from cgkit/light; use quats for dir and rotation in turtlemc
correct turnBy(), adjust Turtle constructor,  replace lean by tilt
Manual diff of 3d-tom branch. Includes rebase from master. Moving of
deps and turtle* files into lib.
Fixed examples' paths and settings path in turtlecraft.py
Rebased manual diff from 3d-tom. SUCH COMPLEX :|
Moved recalc of self._rot() to after rotateVec() cos of pass by ref bug. Need better tests as I only discovered bug after running in minecraft itself
Added test for 2x2 cube
Merged 3d branch