Issy should reject wrong domains

[phheim]

Issy should not allow symbolic games that use location domains with more than current-step program variables.

For example, it should reject

state int x

game Safety from l {
    loc l 1 with [x' = 0] // <- this is bad
    from l to l with true
}

and

input int i
state int x

game Safety from l {
    loc l 1 with [i > 0] // <- this is bad
    from l to l with true
}