Move tempword and currentletter off of scriptclass

There's no reason for these temporary variables to be a permanent part
of the class itself.

desktop_version/src/Script.h

@@ -57,8 +57,6 @@ public:
 
     int scriptdelay;
     bool running, dontrunnextframe;
-    std::string tempword;
-    std::string currentletter;
 
     //Textbox stuff
     int textx;