Replace io.BytesIO with six.BytesIO for py2.6/2.7 and one StringIO with BytesIO
Merge pull request #326 from interru/py2-fix

Replace io.BytesIO with six.BytesIO for py2.6/2.7
rename call to Headers.to_list -> to_wsgi_list
fix unicode error in parse_cookie -- works both in py2 & py3
Merge pull request #329 from puzzlet/sprint/http

fix unicode error in parse_cookie -- works both in py2 & py3
Merge pull request #327 from puzzlet/sprint/datastructures

rename call to Headers.to_list -> to_wsgi_list