Star imports

This cleans up import * statements (fixes #7)  and begins a test directory using the unittest framework.  The first test module verifies the quadrature rules.  

The modules orientations.py and tens.py both imported * from numpy, creating a huge namespace.  I wrote a script to determine which names were actually used, but it does not recognize comments, so it may err on the side of importing too many names.  By hand, I got rid of some obvious names in comments. I do not have a test module to verify these changes, but I have been using the code without problem. 

Pleas comment.