Support scalar real integer and float multiplication with Complex Vector types

[chrissimpkins]

Add support for scalar multiplication * operator overload that scales the real and imaginary parts with a real integer or float scalar value. The scalar type must be the same type as that used for the real and imaginary parts of the num::Complex number.

This will support:

• num::Complex * all int types
• num::Complex * all float types

and supplements the num::Complex number * num::Complex number multiplication operator overload that was added in #14.