Add relicense agreement from Jim Garlick

RELICENSE/garlick.md

+# Permission to Relicense under MPLv2 or any other OSI approved license chosen by the current ZeroMQ BDFL
+
+This is a statement by Jim Garlick (garlick)
+that grants permission to relicense his copyrights in the libzmq C++
+library (ZeroMQ) under the Mozilla Public License v2 (MPLv2) or any other
+Open Source Initiative approved license chosen by the current ZeroMQ
+BDFL (Benevolent Dictator for Life).
+
+A portion of the commits made by the Github handle "garlick", with
+commit author "Jim Garlick <garlick.jim@gmail.com>", are copyright of
+Jim Garlick.  This document hereby grants the libzmq project team to
+relicense libzmq, including all past, present and future contributions
+of the author listed above.
+
+Jim Garlick
+2019/08/10