upstream changes from latest tornado (3.1.1)
Merge pull request #415 from minrk/tornado-upstream

upstream changes from latest tornado (3.1.1)
Merge pull request #416 from minrk/33consts

update 3.3 constants

and enable travis builds with pypy and libzmq-master

fix some CFFI backend bugs found along the way.
Added monitor method to socket.
Added a get_monitor_socket method. Made tests work.
Added zmq_socket_monitor to zmq_compat.h
Fixed decode format and added comment about architecture.
Added simple example for socket monitoring.
Added get_monitor_message and fixed test version skipping.

Added get_monitor_message in zmq/utils/monitor.py.
Adapted tests to use get_monitor_message.
Fixed test skipping in test_monitor.py.
Adapted example to new get_monitor_message function.
Fixed licencese.
Used _check_rc.
Fixed last bugs from list.
Adapted version checks for libzmq 3.3 use only.
Fixed version checks for monitoring support.
Changed ip addresses to loopback and added some more output.
Made example BSD licensed.
Fixed skip to libzmq version 3.3.
modernize simple_monitor example
update monitor test

validate NotImplementedError