minimal dwm added

dwm/util.h

@@ -0,0 +1,8 @@
+/* See LICENSE file for copyright and license details. */
+
+#define MAX(A, B)               ((A) > (B) ? (A) : (B))
+#define MIN(A, B)               ((A) < (B) ? (A) : (B))
+#define BETWEEN(X, A, B)        ((A) <= (X) && (X) <= (B))
+
+void die(const char *fmt, ...);
+void *ecalloc(size_t nmemb, size_t size);