ignore pyc files and vim .swp files
Follow the specifications [1][2] and allow service secret keys to be empty

[1] http://tools.ietf.org/html/rfc5849#section-3.4.4
[2] http://tools.ietf.org/html/draft-ietf-oauth-v2-31#section-2.3.1
Only force Content-Length to be 0 if signature_type is not BODY
Do not limit api() arguments that are passed to requests.requests() as
it to params, data and headers.
add Launchpad service