Merge pull request #992 from hurtonm/master

Define i_properties interface
Allow to set up a source address and port for outgoing tcp connections in zmq_connect()

Few examples:
tcp:://192.168.0.4:55555;192.168.0.254:1234
tcp:://192.168.0.4:0;192.168.0.254:1234
tcp:://eth2:55555;192.168.0.254:1234
Merge pull request #993 from klnikita/src_addr_connect

Allow to set up a source address and port for outgoing tcp connections in zmq_connect
Port 9999 is unsafe for tests
Problem: generates incompatible libzmq.so.3.1.0

See https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=743508

The ABI in fact changed in two significant ways, one with inproc
connects, and one with socket monitoring

Solution: generate libzmq.so.4.0.0 library instead.

This change should be backported to zeromq-4.x
Merge pull request #995 from hintjens/master

Bumped ABI version to 4.0.0
Add metadata to received messages