Problem: zmq_connect fails after disconnect due to RECONNECT_IVL == -1

Problem: tests where client should receive an ERROR sometimes do not

Solution: when a connection breaks and ZMQ_RECONNECT_IVL is set to -1,
which means a reconnection will not be attempted, send a message from
the I/O thread to the application thread to make the socket call
term_endpoint, which is the equivalent of manually calling
zmq_disconnect.
This way subsequent zmq_connect call to the same endpoint will attempt
again to do a connection.
Otherwise, for some socket types like SUBs, those new connects will
fail as the endpoint is recorded, despite the connection having been
permanently closed.

Add test cases to exercise this corner case with TCP and IPC.

receive an ERROR (probably because the connection is closed before)

Solution: wait for client-side monitor events before closing the client
socket

Fixes #2705

Problem: documentation of ZMQ_ZAP_DOMAIN is wrong

Solution: fix documentation

Problem: missing tests and inconsistent behaviour for ZAP corner cases

Solution: added tests

mechanisms

Solution: uniformly require a ZAP domain to be set to activate ZAP
handling, clarify comment on Stonehouse pattern

Solution: added test & some improvements of test utils

Solution: emit events as expected by tests, and refuse connections when
ZAP is required but no handler started

Addresses #2711 partially

Solution: added test case for NULL/PLAIN/CURVE

Problem: CentOS 6 build fails

Solution: use same autoconf workaround as for Debian 7, and manually
create the config directory

Update AUTHERS File

RELICENSE: Google, Inc.

Relevant commits: ddb82a54, 68f5926e

Also adds AUTHORS entry that should have been part of the previous commits.

Problem: duplicated socket_poller::wait() code

zmq::socket_poller_t::wait() had an important set of common lines
between POLL and SELECT variant.

Solution: refactor zmq::socket_poller_t::wait() and add the
following methods:

zmq::socket_poller_t::zero_trail_events()
zmq::socket_poller_t::check_events()
zmq::socket_poller_t::adjust_timeout()
Signed-off-by: Marc Sune <mardevel@gmail.com>

Revert "Problem: term "identity" is confusing"

Problem: term "identity" is confusing

Solution: use "routing_id" instead

Solution: Replaced by "routing id"

Solution: change docs to refer to "Routing id"

Solution: Renamed, but support querying the property by its old name

Solution: Replaced by "routing_id"

Solution: renamed routing_id fields in pipe_t, renamed ZMQ_CONNECT_RID to ZMQ_CONNECT_ROUTING_ID

Solution: replace by "routing id"

Problems: typos in proxy_steerable stats

Solution: fix it

Solution: fix it

Problem: proxy_steerable STATISTICS returns conflated buffers

Solution: split each stat into its own frame, to make it simpler and
easier to use it, especially from high level bindings

Problems: proxy stats test break 32bit build, not declared as draft

Solution: ifdef it until it's declared stable

Solution: trucate 64 bit stats in test_proxy, as it's much easier than
to try and print 64 unsigned integers in a portable way

* Issue #2736: Add STATISTICS command to zmq_proxy_steerable()

Variable is assigned but is not used until the end of the function