Complex-Math: Handle Operations with Scalars

First feature from @BeyondEspresso 's pull #597.

Updated the complex-math library in the radiation-plugin to handle all basic calculations (+,-,*,/) and assignment from scalars.
Btw IMO: `other.abs_64()` is a really bad style.

`object.opartion` means in general that we change the `object`, but in this case we get something back and not change `object`