Problem: need to collect grants to relicense under MPLv2

Solution: kick off process with grant from iMatix

RELICENSE.md

+# Permission to Relicense under MPLV2
+
+This document collects grants from firms that hold copyrights in ZeroMQ. Please add new firms at the start. Each patch must be made with a GitHub handle that guarantees identity of the signatory.
+
+## iMatix Corporation
+
+This is a statement by iMatix Corporation sprl (iMatix) that grants permission to relicense its copyrights in the libzmq C++ library (ZeroMQ) under the Mozilla Public License v2 (MPLv2).
+
+1. The original ZeroMQ codebase was developed from 2007-2009 by FastMQ Inc. (FastMQ) in Slovakia, which held all copyrights in code written by its staff.
+
+2. On 2009-11-01, iMatix exercised an option to acquire FastMQ and its assets,
+including ZeroMQ. On or before 2010-01-05 the FastMQ copyrights in ZeroMQ were
+transferred to iMatix ([commit](https://github.com/zeromq/libzmq/commit/4f6baf4dde627656b63cc4e2acdb78a8577ba640)). The FastMQ legal entity was subsequently liquidated.
+
+3. Between 2009 and 2016, iMatix has continued to add contributions to ZeroMQ under the GitHub handle 'hintjens'.
+
+4. This grant therefore covers what remains of the original FastMQ codebase plus all later contributions.
+
+5. iMatix hereby grants an irrevocable, global, and fully paid-up license on all its copyrights that exist in ZeroMQ, under the MPLv2.
+
+-Pieter Hintjens
+CEO, iMatix Corporation sprl
+23 April 2016