Fix the reading of the localhost MTU in the HTTP tests

Sometimes the localhost interface has a different name from "lo",
this fix adds a helper function to read the MTU value when the
interface name starts with "lo".
Improve the detection of localhost interfaces for the HTTP test suite
Avoid crashing in cowboy_req on invalid Accept-Encoding header

Certain clients send malformed Accept-Encoding headers, which causes
cowboy_req to crash is compression is enabled.
Use ct_helper for retrieving the loopack interface MTU
Merge branch 'fix/crash-on-invalid-accept-encoding' of git://github.com/soundrop/cowboy
Update erlang.mk
Add support for the webkit deflate frame extension
Merge branch 'feature/websocket-deflate-frame' of git://github.com/soundrop/cowboy
Update Ranch to 0.8.4
Add asn1 to the list of applications to be started for SSL

Required since R16B01. And apparently needed in some cases before.
Ignore deprecation warning for crypto:sha/1 for now

We can change this call when we start supporting only R16B+,
which may happen when R17B is released or some time before.
Update AUTHORS
Update CHANGELOG
Update to 0.8.6
Fix compilation < R16B01
Reword the clean erlang code part

We don't care about parameterized modules anymore. They're gone!
Greatly improve the guide introduction
Remove unknown keys from .app.src file
Minor corrections of the guide
Merge branch 'fix_docs' of git://github.com/pannonia-technologies/cowboy