Merge pull request #3410 from Quuxplusone/license

RELICENSE: Arthur O'Dwyer grant

RELICENSE/Quuxplusone.md

+# Permission to Relicense under MPLv2 or any other OSI approved license chosen by the current ZeroMQ BDFL
+
+This is a statement by Arthur O'Dwyer
+that grants permission to relicense its 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 "Quuxplusone", with
+commit author "Arthur O'Dwyer <arthur@push.am>", are copyright of Arthur O'Dwyer.
+This document hereby grants the libzmq project team to relicense libzmq, 
+including all past, present and future contributions of the author listed above.
+
+Arthur O'Dwyer  
+2019/02/17