Httpy

Added ProtoVersion class to easily implement more HTTP versions in future.
Things that are new:

- ProtoVersion class
- HTTP11Sender class
- HTTP11Recver class
- HTTP11 class
- http_version kwarg of request()
- less of spaghetti code in _raw_request()

Added more functionality to the `WebSocket` class.

Things that are new:

- `WebSocketFile` class
- `WebSocket.makefile()` method
- `WebSocket.reconnect()` method
- WebSocket modes

Added `string` property of `Response`

Added support for Sessions
**The ``_binappendstr()`` function now packs 16-bit ints, needed to write long cookies**

Added support for WebSockets

v.1.0.3