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
Fixed issue #500
Merge pull request #509 from hintjens/master

Added IPv6 option to context
LIBZMQ-497 there could be unsent bytes in encoder

When we send a large message, the message can be splitted into two chunks.
One is in the encoder buffer and the other is the zero-copy pointer.
The session could get the term before the last chunk is sent.
Merge pull request #510 from miniway/master

LIBZMQ-497 there could be unsent bytes in encoder
Corrected linking error in MSVC build

MSVC build fails with linking errors for unresolved symbols SetSecurityDescriptorDacl and InitializeSecurityDescriptor in signaler.obj
Adding the relevant link library (Advapi32.lib) to VCLinkerTool fixes this (tested MSVC2010 on XP and Win7)
Merge pull request #511 from mjasperse/patch-2

Corrected linking error in MSVC build