Of course people still "can" distributed the sources under the
LGPLv3. However we provide COPYING.LESSER with additional grants.
Solution: specify these grants in the header of each source file.
Allows non-C/C++ based clients easy access to the peer's IP address via
zmq_msg_gets(&msg, "Peer-Address") instead of zmq_msg_get(&msg, ZMQ_SRCFD)
followed by calls to getpeername and getnameinfo
