==========================
ADDED:
* Comparison operator support!
* Polynomial functions:
`poly_divide`, `poly_divmod`, `poly_reminder`, `sortable_proxy`.
* Numpy functions:
`amax`, `amin`, `argmin`. `argmax`, `greater`, `greater_equal`,
`less`, `less_equal`, `max`, `maximum`, `min`, `minimum`.
* Lots of extra tests.
CHANGED
* String representation changed from insertion order to Graded-reverse
lexicographically.
* New comparison and poly-division and derivative chapter in Sphinx, instead
of poly-functions.
* Move global options into common file with interfaces:
`get_options`, `set_options` and `global_options` (context manager).