PolyRing now forwards to PrimeField. Also got rid of PolyRing::getMonomialPool() in an effort to reduce the size of the interface of PolyRing.
PolyRing can now forward to MonoMonoid and PrimeField for almost everything. Added lots of new methods on those two to make that possible.
Added test to the new methods on MonoMonoid and PrimeField.