Fixed expressions to be able to do math with nested expressions.

__for.cpp

@@ -18,7 +18,6 @@ namespace jet {
       if(variableDefined(coreutils::ZString("step"))) {	   
 	 step = variables["step"].asDouble();
       }
-      std::cout << "start: " << counter << "; end: " << end << "; step: " << step << std::endl;
       for(double ix = counter; ix <= end; ix += step) {
 	 if(nameDefined) 
 	   variables[variables["name"]] = ix;