Merge pull request #745 from ricnewton/master

Get maximum number of sockets it can handle from poller_t
Merge pull request #746 from ricnewton/master

Make FD_SETSIZE = ZMQ_MAX_SOCKETS_DFLT + 1 so there is room for the reaper socket
Signal that the peer performed orderly shutdown
Merge pull request #747 from hurtonm/master

Signal that the peer performed orderly shutdown
Added ignore test case
Merge pull request #748 from hintjens/master

Added ignore test case
Fix socket creation above sistem limits for all 'other' OS not covered by eventfd, windows or vms; enhanced test to create sockets up to a bigger limit to really test hitting the OS limit
Merge pull request #749 from davipt/fix-001-test_many_sockets_and_mac_open

Fix socket creation above sistem limits for all 'other' OS not covered b...
Update signaler make_fdpair to set file descriptors to -1 when too many files are open using socketpair.
Merge pull request #750 from mattconnolly/master

Update signaler make_fdpair to set file descriptors to -1 when too many ...
Revert "Make FD_SETSIZE = ZMQ_MAX_SOCKETS_DFLT + 1 so there is room for the repear socket."

This reverts commit 0b92831b2a82c3bbc0e9371662c546b94915a3ea.