feat: factories can depend on the presence of types

Refactors each TypeDispatcher to have its own separate collection
  of types. Add isnan function which returns a boolean if that type
  is present, otherwise returns the number 1 for true, and 0 for fase.

src/__test__/numbers.spec.js

@@ -6,4 +6,8 @@ describe('the numbers-only bundle', () => {
       assert.strictEqual(math.quotient(5, 3), 1)
       assert.strictEqual(math.square(-3), 9)
    })
+   it('uses 1 and 0 instead of true and false', () => {
+      assert.strictEqual(math.isnan(-16.5), 0)
+      assert.strictEqual(math.isnan(NaN), 1)
+   })
 })