Fix payload length handling (RFC 6455, section 5.2)

Fixes Autobahn Testsuite websockets case 1.1.2
Use readexactly method, because payload maybe choped up

Fixes Autobahn Testsuite websockets cases 1.1.8, 1.2.8
Add set_cookie method
Fix response test
Merge pull request #1 from etataurov/fixrfc

AutobahnTestsuite
Fix tests on python 3.4
Request handling refactor
Refactor
Remove wsgi
Update README.rst to no longer mention WSGI
New HttpRequest class
Add initial SockJs support
Currently the following SockJs tests fail:
- WebsocketHybi10
- WebsocketHixie76
- JsessionidCookie
- Http10
Handle invalid UTF-8 gracefully
Make sockjs support optional
Fix tests
Fix deps for python 3.3
Fix test imports
Update README
Update
Make on_message a coroutine