Automated control-gate construction

[mtfishman]

I think we could have an automated control-gate construction by parsing the gate name, checking if it starts with "C", and then stripping the rest of the name and using the rest of the name to make the gate that will be controlled (for example "Cmy_gate" becomes a control gate from "my_gate"). We could do that only if the full name of the gate doesn't have a gate definition.