Some small incremental updates since October. The biggest changes are in the drawing functions---see the documentation for examples.
- Rewrote the tree-pair drawing functions from scratch. Can now render an automorphism in any G_{n, r}---previously only G_{2,1} worked.
- Can also plot an automorphism as a function from the interval to itself.
- Fixed a bug in Word.as_interval --- was completely broken for words that didn't start with x1
- Fixed a bug where the periodic conjugacy test could incorrectly conclude that two auts were not conjugate