Fixes for return statement, make Evaluate function on script return value

src/ScriptType.hpp

@@ -110,6 +110,10 @@ public:
         return _returnType;
     }
 
+    void SetReturnType(shared_ptr<ScriptType> t){
+        _returnType = t;
+    }
+
     vector<shared_ptr<ScriptType>> GetParameterTypes(){
         return _parameterTypes;
     }