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)
I pretty much never see `np.matrix` used... what's the advantage?

The disadvantage is its lack of use elsewhere, and the risk of operators not working the way people expect if they don't read the docstring carefully. In this sense, having `*` mean "matrix multiply" instead of `ndarray` "broadcast multiply" can be seen as a disadvantage. It's also a bit weird if we use `np.array` everywhere else and `np.matrix` for this one thing, so I'm -1 on making this change.