Code for review: New wigner coupling coefficient code and rotation matrix code

[Brian Gough]

Jonathan Underwood writes:
 > This code can be downloaded from <http://physics.open.ac.uk/~ju83>. 
 > wigner.c contains the code, gsl_sf_wigner.h is the header file, and there 
 > is a modified test_sf.c including tests for this code.

Nice -- the code looks clean and well organized.
I will study the details shortly.

-- 
Brian Gough