Make charsets parsing more relaxed

Certain user agents send invalid Accept-Charset headers, like the
following: "ISO-8859-1;utf-8;q=0.7,*;q=0.7"

The user agent with which this behavior was observed presented itself
with the User-Agent string: "Mozilla/5.0 (Windows; U; Windows NT 5.1;
en-US; rv:1.9) Gecko/2008052906 Firefox/3.0" Although this doesn't
appear to be correct. The request might have been mangled by a
transparent proxy.
Add file option to cowboy_http_static
Only ignore slashes in cookie values for the path

* Ensures cookie encoding errors are caught earlier
* Fix separator misspelling
Small updates to the ROADMAP and doc comments
Make multipart code use stream_body
Fix a bug preventing 'onresponse' from being called on errors
Merge branch 'fix/relax-conneg-parsing' of https://github.com/tillitech/cowboy
Merge branch 'serve-static-file' of https://github.com/klaar/cowboy

Fix alphabetical order since @klaar seems to have issues with it. ;)
Merge branch 'cookie_slash' of https://github.com/bfrog/cowboy
Remove a dumb warning when running the tests
Update version to 0.6.0

Also update the CHANGELOG and copyright years.
Add an Hello World example
Add a simple Static File Server example
REST: Fix charset matching
REST: Normalize content types accepted

Same as content types provided, we accept the <<"application/json">> form.
Add support for Expect: 100-continue

This makes uploading files with curl a lot faster than without.
Add a GET echo example
Add a POST echo example
Add a Chunked Hello World example
Add a REST Hello World example