Super-Rogue: fix some out-of-range constants.

Constants K_ARROW etc., for causes of death other than monsters, are in
the 240-255 range.  They were often passed to functions taking char,
which is usually signed, making the values out of range.

The function declarations have been changed to unsigned char, which is
also the type used by the scoreboard code.

srogue/pstats.c

@@ -21,7 +21,7 @@ int hungdam(void);
  *	Changes players hit points
  */
 void
-chg_hpt(int howmany, bool alsomax, char what)
+chg_hpt(int howmany, bool alsomax, unsigned char what)
 {
 	nochange = FALSE;
 	if(alsomax)