Another take on LIBZMQ-568 to allow filtering IPC connections, this time
using ZAP.  This change is backward compatible.  If the
ZMQ_ZAP_IPC_CREDS option is set, the user, group, and process IDs of the
peer process are appended to the address (separated by colons) of a ZAP
request; otherwise, nothing changes.  See LIBZMQ-568 and zmq_setsockopt
documentation for more information.

See https://github.com/zeromq/issues/pull/7Signed-off-by: Shannen Saez <shannenlaptop@gmail.com>

This reverts commit 0b92831b.

This reverts commit e5baf1e0.

This reverts commit 11b699e7.

* ZMQ_REQ_STRICT was negative option (default 1) which goes against
  the standard, where defaults are zero. I renamed this to
  ZMQ_REQ_RELAXED.

* ZMQ_REQ_REQUEST_IDS felt clumsy and describes the technical solution
  rather than the problem/requirement. I changed to ZMQ_REQ_CORRELATE
  which seems more explicit.

* The ZMQ_CONNECT_DELAY option was renamed to ZMQ_IMMEDIATE

README file moved to GitHub format and extension, drop from packaging and default to NEWS file for popup.

Fix build on windows, uint isn't a standard type, unsigned int is.