Add O (operator) modules to all numerical modules

[jasone]

The Real module has Real.O, which makes local opens a convenient way of performing floating point operations without risk of namespace clashes. For example, let min = 3. in Real.O(min + 4.) doesn't trip on Real.min (contrived, but shows the brittleness of Real.(...)). This same problem can occur with any numerical type for which we might use a local open in order to access an infix operator. Therefore we should universally provide .O submodules for numerical modules.