Improve how to redefine max moves in 1991/rince

By a Makefile variable using

    make MAXMOVES=N clobber alt

where N is an integer will set the maximum number of moves one may make
in the second alt version (rince.alt2.c) (the first alt version
rince.alt.c has no limit).

1991/rince/Makefile

@@ -58,7 +58,7 @@ ARCH=
 
 # Defines that are needed to compile
 #
-CDEFINE= -DMAX_MOVES=484
+CDEFINE= -DMAX_MOVES=${MAXMOVES}
 
 # Include files that are needed to compile
 #
@@ -137,11 +137,13 @@ ${PROG}: ${PROG}.c
 alt: data ${ALT_TARGET}
 	@${TRUE}
 
+# variable to control max number of moves
+MAXMOVES=484
 ${PROG}.alt: ${PROG}.alt.c
 	${CC} ${CFLAGS} $< -o $@ ${LDFLAGS}
 
 ${PROG}2.alt: ${PROG}.alt2.c
-	${CC} ${CFLAGS} $< -o $@ ${LDFLAGS}
+	${CC} ${CFLAGS} -DMAX_MOVES=${MAXMOVES} $< -o $@ ${LDFLAGS}
 
 # data files
 #