Add license to contrib/untgz.
A zlib license was agreed to by the authors.
diff --git a/contrib/untgz/untgz.c b/contrib/untgz/untgz.c
index 3e53097..7857921 100644
--- a/contrib/untgz/untgz.c
+++ b/contrib/untgz/untgz.c
@@ -4,6 +4,22 @@
* written by Pedro A. Aranda Gutierrez <paag@tid.es>
* adaptation to Unix by Jean-loup Gailly <jloup@gzip.org>
* various fixes by Cosmin Truta <cosmint@cs.ubbcluj.ro>
+ *
+ * This software is provided 'as-is', without any express or implied
+ * warranty. In no event will the authors be held liable for any damages
+ * arising from the use of this software.
+ *
+ * Permission is granted to anyone to use this software for any purpose,
+ * including commercial applications, and to alter it and redistribute it
+ * freely, subject to the following restrictions:
+ *
+ * 1. The origin of this software must not be misrepresented; you must not
+ * claim that you wrote the original software. If you use this software
+ * in a product, an acknowledgment in the product documentation would be
+ * appreciated but is not required.
+ * 2. Altered source versions must be plainly marked as such, and must not be
+ * misrepresented as being the original software.
+ * 3. This notice may not be removed or altered from any source distribution.
*/
#include <stdio.h>
