I've been trying all day to get a "request token" from the dropbox rest-api. Basically I'm trying to perform step 1 at https://www.dropbox.com/developers/blog/20/using-oauth-in-plaintext-mode:   " 1. Make an API call for a request token: POST https://api.dropbox.com/1/oauth/request_token   Your HTTP request should have the following header: Authorization: OAuth oauth_version="1.0", oauth_signature_method="PLAINTEXT", oauth_consumer_key="<app-key>", oauth_signature="<app-secret>&a