Split onground/onroof into visual and logical variables

I will need to separate these into two different variables because I
will need to move logical onground/onroof assignments to the start of
gamelogic() - if I kept them together, however, that would change the
visuals of onground/onroof, which I want to keep consistent with 2.2.

desktop_version/src/Ent.h

@@ -49,6 +49,7 @@ public:
     int onground, onroof;
     //Animation
     int framedelay, drawframe, walkingframe, dir, actionframe;
+    int visualonground, visualonroof;
     int yp;int xp;
 
     Uint32 realcol;