Made changes to bring NumericEqualityConstraint into TypeCheckedTripleEquals and
ConversionCheckedTripleEquals. Testing done in the REPL. Must add tests still.
Added two implicits to allow Seq's to be compared with Arrays.
Decided to use CooperatingNumeric to make sure it always works. Scala's Numeric
isn't sealed, so anyone can implement it, and that doesn't mean it participates
in the cooperative equality. CooperativeEquality is sealed, so it does ensure that.