Log Message:
Update zeromq to 2.1.10.

0MQ version 2.1.10 (Stable), released on 2011/10/03
===================================================

Bug fixes
---------

* Fixed issue 140, SWAP failed with assertion failure in pipe.cpp:187
  if the current directory was not writeable. Behavior now is to return
  -1 at zmq_setsockopt in this situation.

* Fixed issue 207, assertion failure in zmq_connecter.cpp:48, when an
  invalid zmq_connect() string was used, or the hostname could not be
  resolved. The zmq_connect() call now returns -1 in both those cases.

* Fixed issue 218, sockets not opened with SOCK_CLOEXEC, causing fork/exec
  to sit on sockets unnecessarily.

* Fixed issue 250, build errors on Windows.

* Fixed issue 252, assertion failure in req.cpp:87 and req.cpp:88.

* Fixed issue 261, assertion failure in kqueue.cpp:76 on OS/X.

0MQ version 2.1.9 (Stable), released on 2011/08/29
==================================================

Bug fixes
---------

* Fixed issue 240, assertion failure in pgm_socket.cpp:437.

* Fixed issue 238, assertion failure in zmq.cpp:655, when zmq_poll is
  used on an empty set, on Windows.

* Fixed issue 239, assertion failure in zmq.cpp:223, when ZMQ_SWAP was
  used with explicit identities and multiple SUB sockets.

* Fixed issue 236, zmq_send() and zmq_recv() did not always return
  error conditions such as EFSM properly. This bug was introduced in
  version 2.1.8 by the backport of changes for issue 231.

Building
--------

* 0MQ support for Android added (Bill Roberts, Mikko Koppanen).

0MQ version 2.1.8 (RC), released on 2011/07/28
==============================================

Bug fixes
---------

* Fixed issue 223, assertion failure in tcp_connecter.cpp:300 when
  connecting to a server that is on an unreachable network (errno is
  equal to ENETUNREACH).

* Fixed issue 228, assertion failure at rep.cpp:88 when HWM was reached.

* Fixed issue 231, assertion failure at mailbox.cpp:183 when too many
  pending socketpair operations were queued (major backport from 3.0).

* Fixed issue 234, assertion failure at mailbox.cpp:77 when Ctrl-C was
  used (only affected git master following backport for 231).

* Fixed issue 230, SIGPIPE killing servers when client disconnected, hit
  OS/X only.

Note: this release was renamed "release candidate" due to issue 236,
fixed in 2.1.9.