remove ExclamationToken from context independent tokens to

prevent error for:
!+! a b -> a
!+! a b = a

frontend/scanner.icl

@@ -434,7 +434,6 @@ notContextDependent token
 	SquareCloseToken	-> True
 	SemicolonToken		-> True
 	CommaToken			-> True
-	ExclamationToken	-> True
 	ClassToken			-> True
 	InstanceToken		-> True
 	OtherwiseToken		-> True