Constants needed in EA

[berndbischl]

In many cases one might like to have a couple of "constants" that are accessible in the generators and operators. e.g. the size of the represented candidate or some other stuff.

Of course I can probably have some global vars for this. But this is bad design and will not work if I parallelize or whatever. So maybe allow to add a list "custom.consts" to the control?
Because this is probably passed down to all function anyway?