Refactored util/transforms.py translate, scale and rotate to just return

Refactored translate, scale and return to just return a matrix to be multiplied instead of the matrix multiplication being done in the method

Adapted scenen linear transforms as appropriate

Adapted examples as appropriate (except for ipython notebooks, cannot test those)
This is more API than is needed for such a simple function. The deg/rad conversion is so common that our users are unlikely to be frustrated if they are forced to add in a scale factor. Let's just choose `rotate(deg)` or `rotate(rad)` and be done with it. My vote is on degrees for consistency with opengl.