CONTRIB: merge ip6range with iprange

No need to have two separate sub-projects doing the same thing, let's
merge them.
diff --git a/contrib/ip6range/Makefile b/contrib/ip6range/Makefile
deleted file mode 100644
index 55849b6..0000000
--- a/contrib/ip6range/Makefile
+++ /dev/null
@@ -1,13 +0,0 @@
-CC       = gcc
-OPTIMIZE = -O3
-LDFLAGS  = -s
-
-OBJS     = ip6range
-
-all: $(OBJS)
-
-%: %.c
-	$(CC) $(LDFLAGS) $(OPTIMIZE) -o $@ $^
-
-clean:
-	rm -f $(OBJS) *.o *.a *~
diff --git a/contrib/iprange/Makefile b/contrib/iprange/Makefile
index b3c72ed..13598d8 100644
--- a/contrib/iprange/Makefile
+++ b/contrib/iprange/Makefile
@@ -1,8 +1,8 @@
-CC       = gcc
+CC       = cc
 OPTIMIZE = -O3
 LDFLAGS  = -s
 
-OBJS     = iprange
+OBJS     = iprange ip6range
 
 all: $(OBJS)
 
diff --git a/contrib/ip6range/ip6range.c b/contrib/iprange/ip6range.c
similarity index 99%
rename from contrib/ip6range/ip6range.c
rename to contrib/iprange/ip6range.c
index 62d46e5..2ffd490 100644
--- a/contrib/ip6range/ip6range.c
+++ b/contrib/iprange/ip6range.c
@@ -314,7 +314,7 @@
 		"\n", argv0);
 }
 
-main(int argc, char **argv)
+int main(int argc, char **argv)
 {
 	char line[MAXLINE];
 	int l, lnum;
@@ -393,4 +393,5 @@
 			convert_range(&sa, &da, he, NULL);
 		}
 	}
+	return 0;
 }