Merge pull request #758 from hintjens/master

Fixed test_many_sockets
Merge pull request #759 from hintjens/master

Moved version macros to top for better visibility
Move linger test to issue repo.

See https://github.com/zeromq/issues/pull/7

Signed-off-by: Shannen Saez <shannenlaptop@gmail.com>
Merge pull request #760 from shancat/move_linger_test

Move linger test to issue repo.
Add ability to set and get DSCP socket option
tidy up
Merge pull request #761 from claws/add_dscp_sockopt

Add ability to set Differential Services Code Point socket option
Fix windows build for type of service.
Merge pull request #762 from ricnewton/master

Fix windows build for type of service.
make win32 signaler support ephemeral ports
Merge pull request #765 from pijyoi/master

make win32 signaler support ephemeral ports
Fix issue #763
Merge pull request #766 from hurtonm/master

Fix issue #763
changing zmq_proxy_steerable to not use null terminated strings
Merge pull request #768 from Talksum/master

changing zmq_proxy_steerable to not use null terminated strings
Code cleanup
Merge pull request #770 from hurtonm/master

Code cleanup
Updated documentation for zmq_disconnect() and zmq_setsockopt().
Intial IPC accept filter support.

Adds sets of process (Linux only), user, and group IDs for filtering
connections from peer processes over IPC transport.  If all of the
filter sets are empty, every connection is accepted.  Otherwise,
credentials for a connecting process are checked against the filter sets
and the connection is only accepted if a match is found.

This commit is part of LIBZMQ-568 and only adds the filter sets and
implements the filter in the IPC accept method.  The interface for
adding IDs to filter sets are included in a separate commit.

IPC accept filtering is supported only on Linux and OS X.
Add IPC accept filter socket options.

Adds ZMQ_IPC_ACCEPT_FILTER_{PID,UID,GID} socket options to add processs,
user, and group IDs to the IPC filter sets. Fixes LIBZMQ-568.