Implementing Numbers with js-numbers

Added support for big nums into the language.
Tests taking advangtage of the bignum number space are forthcoming

Updated existing tests to reflect the fact that numbers now have bignums
with new matches:

toBigEqual: compares a big num result with a js number
toBeBig: compares a big num result with another bignum
More bignum tests
Merge branch 'nwo' of https://github.com/brownplt/pyret-lang into nwo

Merging changing of number dict with the addition of bignums

Conflicts:
	js/runtime-anf.js
Fixed Number Tests for New Method Syntax, Boolean Aliasing

PBoolean had an aliasing bug in clone since makeBoolean no longer
creates a fresh boolean. Changed it to new PBoolean to ensure that
myBool.clone !== myBool.

Updated number tests to reflect the new curried method form