Blind fix of delta operator

[Vurv78]

• Fixed oversight with delta as I was trying to move the functionality from the parser to the compiler, which made using a delta variable before the compiler saw the $ operator being used treat it as a normal variable.
• Fixed delta variables across includes which wouldn't be tagged as delta variables (I think this might've been an issue even before the compiler rewrite, I just happened to think of it.)

#include "Include_me"

Var = 0

printDelta()

@name Include me
@persist Var

Var = 5

function printDelta() {
    print($Var)    
}

So this code doesn't error now.

@CheezusChrust