I traced memory leaks found using AddressSanitizer down to these.

Fixed wrong message::init arguments.

Set the ZMQ_HEARTBEAT_TIMEOUT to default to the value of
ZMQ_HEARTBEAT_IVL if it's not explicitly set.
Change the units of ZMQ_HEARTBEAT_TTL to milliseconds in the API
and round down to the nearest decisecond so that all the options
are using the same units.
Make the maximum heartbeat TTL match the spec (6553 seconds)

This commit adds ZMTP connection heartbeats described in
http://rfc.zeromq.org/spec:37/ZMTP.

new allocation caused reference counters to lose track on copy

Problem: zmq_setsockpt() returns success when changing the
HWM after a bind or connect() even though the call has no effect.

Solution: Introduce a failing test a reminder we need to patch it.

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.

When targeting a version of Windows less than Windows Vista, the
security tests fail to build. Added a check for Windows version
and substituted inet_pton for inet_addr. Fixes libzmq issue #1396.

Solution: add settle pause after zmq_connect

Fixes #1340

added version to builds
other cleanup

Solution: raise timeouts from 100-150 msec to 250 msec

ZMQ_INVERT_MATCHING reverses the PUB/SUB prefix matching. The subscription
list becomes a rejection list. The PUB socket sends messages to all
connected (X)SUB sockets that do not have any matching subscription.

Whenever the option is used on a PUB/XPUB socket, any connecting SUB
sockets must also set it or they will reject everything the publisher
sends them. XSUB sockets are unaffected because they do not filter out
incoming messages.