Logical Operators for Signals/Rules

[JTAmos]

Add the ability to define a signal or rule with logical operators. For example:

siglong  = @signal MAMA ↑ FAMA || MAMA == FAMA

[gruberdev]

Ths functionality difers from:
siglong = @signal MAMA ↑ FAMA how?

I was almost sure there were signals implemented as logical operators, but I never tested them to be sure.