Use both query and form to oauth sign calculation.

And also handles array values node's querystring.parse.
Simpler params merge and append realm to auth header

Use querystring.parse to build oauth request params.
Now realm prop in oauth options will be included in authorization
header.
update oauth-sign to 0.4.0
Merge pull request #996 from bengl/oauthsig

Wrong oauth signature when multiple same param keys exist [updated]