Improving Galois groups and implementing Artin representations in Sage.

This code is still early on in development. It does however have doctests that can be used as examples.

One example I particularly like is for the octic field defined by

x^8 + 24x^6 + 144x^4 + 288*x^2 + 144.

This field is the unique quaternion octic CM field with class number 2 (a result of Louboutin (1996); no such fields can have class number 1). The code computes that the global Artin root number of the two-dimensional irreducible Artin representation is -1.