- made DukeActor::timetosleep unsigned.

Although mostly theoretical it is possible for this to overflow and render the actor non-functional.
If the value is unsigned the overflow will wrap around to 0 which is not critical.

source/games/duke/src/types.h

@@ -43,7 +43,7 @@ public:
 	uint8_t spriteextra;	// moved here for easier maintenance. This was originally a hacked in field in the sprite structure called 'filler'.
 	short attackertype, hitextra, movflag;
 	short tempval, dispicnum, basepicnum;
-	short timetosleep;
+	unsigned short timetosleep;
 	DVector2 ovel;
 	DAngle hitang;
 	double floorz, ceilingz;