add patched tornado_sockjs to gaffer

This version is patched to use tornado_pyuv and add support to python 3.
add simple websocket client

Future communication between the gaffer HTTP clients and the HTTP api
will use streams to communicate with feeds.
add license
compat with py2.7
make the example using pyuv
make the websocket connection explicit.

add the strat method to the WebSocket object
add websocket client test & fix sockjs API

Fixes:

- This change make sure that we can close the loop when finishing the
application: the session cleanup loop & stats aggregations aren't
blocking anymore.
- Pass headers as latin1 (http spec)
- Graceful shutdown of the client is now optional and disabled by
  default.
fix import
add 3.3 to travis tests
fix missing import under py27
fix whitespaces
use passed graceful_shutdown as timeout
add version handler
add `gaffer.queue.AsyncQueue`

This object allows an object to received asynchronously any messages sent by
others threads or from others objects. `send` is always threadsafe.
useless var
introduce the internal messagin queue
patch the loop to be comptible with 0.9.

Hopefully we can remove this patch soon when the 0.10 is out.
fix consistancy between internal pids and os pids

In Gaffer a pid is an internal process id that we increment along the time. os
pids are pids given by the OS. This change make sure we have a clear
distinction betwwen them even in the code. So now:

    Process.pid = internal pid
    Process.os_pid = os pid

Same change apply to the info dict.
move the pid resource to its own module.
s/_cached_pid/_os_pid/g