Solution: change .travis.yml to build "android" instead of "qt-android"

Problem: builds/qt-android name is inaccurate

Solution: rename to simple builds/android.

Add special interface to represent local VMCI context.

Add mailmap file

Add missing support for IPv6 link local addresses

Problem: zmq_vmci man page claims to be zmq_ipc man page

Don't build VMCI by default.

Solution: fix this.

Solution: disable vmci by default
Fixes issue #1655

Solution: do not include vmci header outside of vmci IFDEF
Fixes issue #1655

Add the VMCI transport.

VMCI transport allows fast communication between the Host
and a virtual machine, between virtual machines on the same host,
and within a virtual machine (like IPC).

It requires VMware to be installed on the host and Guest Additions
to be installed on a guest.

Adjust start of heartbeat timer

Only start the heartbeat timer when the underlying mechanism is ready to stop cipher streams from trying to encrypt a heartbeat before the handshake has completed. Addresses issue #1601.

fixes #1565: Allow session to flush commands on an engine error

Solution: print test-suite.log if "make check" fails

Currently, a test fails on Travis-CI but that can not be reproduced locally.
Without the contents of the test-suite.log, this is difficult to analyze.

Solution: print test-suite.log if "make check" fails

This is based on the following answer on SO:
http://stackoverflow.com/a/32597140

Fix pipe activation race

This reduces chances of race between writer deactivation and activation.

Reader sends activation command to writer when number or messages is
multiple of LWM. In situation with high throughput (millions of messages
per second) and correspondingly large HWM (e.g. 10M) the difference
between HWM needs to be large enough - so that activation command is
received before pipe becomes full.

Solution: remove `out_batch_size` from src/config.hpp

Solution: remove `out_batch_size` from src/config.hpp

Add new option ZMQ_MULTICAST_MAXTPDU to set PGM_MTU.

Fixes #1646

Problem: router socket can do pipe handover while reading multipart message

Problem: when STREAM socket HWM is reached an assert will happen as metadata is trying to set twice

Solution: change behaviour of tcp_send/recv_buffer_size option