Fix many compiler warnings.

There should only be two changes in behavior:

arogue7/fight.c, arogue7/fight.c: a to-hit bonus is now correctly
applied to characters who are not monks instead of monks who are not
empty-handed.

urogue/fight.c: fixed an interaction with the "debug" macro that could
cause the wrong message to be displayed.

srogue/io.c

@@ -136,8 +136,6 @@ dead_end(char ch)
 int
 readchar(void)
 {
-	char c;
-
 	fflush(stdout);
         return( md_readchar(cw) );
 }