define a dummy EPROTO for platforms that don't use it

This accomplishes the same thing as 2e2ef7fd in a potentially cleaner way.
Merge pull request #502 from ianbarber/master

Add bounds check on upstream XSUB messages
Added tests/test_disconnect_inproc to .gitignore
Fix cmake not linking librt to perf-tools
Merge pull request #504 from o172/master

Adds tests/test_disconnect_inproc to .gitignore
Merge pull request #505 from arsenm/master

Fix perf-tools build on Linux with cmake
Merge pull request #503 from chazmcgarvey/define-dummy-eproto

define a dummy EPROTO for platforms that don't use it
Fix using wrong name for windows.h check in cmake
Merge pull request #506 from arsenm/master

Fix using wrong name for windows.h check with cmake
Removed heap allocation for in zmq_poll for small item sets

Until now, zmq_poll always allocates the poll items on the heap.
Now, small item sets, up to ZMQ_POLLITEMS_DFLT, are stack allocated
and only larger sets are allocated on the heap.
Merge pull request #507 from bjoto/master

 LIBZMQ-498 - Remove heap allocations in zmq_poll for small poll item sets
Updated .gitignore
Added ZMQ_IPV6 option, cleaned up setsockopt code, it was nasty
Various cleanups to test programs
Fixed use of deprecated zmq_init/term
Rewrote raw test completely
Rewrote completely, was bogusly testing EAGAIN
Lots of cleanups to self-tests
* Removed or truncated sleeps so the tests run faster
* Removed dependencies on zmq_utils
* Rewrote a few tests that were confusing
* Minor code cleanups
Fixed issue #499
Merge pull request #508 from hintjens/master

IPv6 related changes and cleanups to test cases