Better handle socket closing with loop handlers

We now read from the socket to be able to detect errors or TCP close
events, and buffer the data if any. Once the data receive goes over
a certain limit, which defaults to 5000 bytes, we simply close the
connection with an {error, overflow} reason.
Add a few directions in the REST chapter in the guide

This is obviously not proper documentation. We will properly document
it when the API stabilizes.
Add a REST point on the roadmap
Fix examples in cowboy_static edoc and guide
Merge branch 'static_doc' of git://github.com/acammack/cowboy
Add a REST example that streams its response
Merge branch 'stream_example' of git://github.com/acammack/cowboy
Fix connection state being ignored for unknown length streaming
Update AUTHORS
Update CHANGELOG
Make cowboy_protocol:resume/6 private
Update to 0.8.0
Make cowboy_http.erl compile with +native

Worked until 27da092
Update websocket handler callback specs

There are some additional terminate reasons exist which are not mentioned
in the specs.
Make cowboy_websocket.erl compile with +native

Worked until cccc0bc
cowbot_req:has_body:/1 improved
Merge branch 'native_compile' of git://github.com/acammack/cowboy
Merge branch 'fix/websocket_callback_specs' of git://github.com/keynslug/cowboy
Merge branch 'has_body_improved' of git://github.com/0xAX/cowboy
Properly pass the handler's state to websocket_terminate/3 on close