That is a very complicated thing. The
140dev framework was constructed for
single-user oauth
Streaming API request. To go
multi-user, you'll need to request twitter for
credentials for each user that enters your website (
access_token and
access_token_secret), store them in a
database an also your app has to be able to identify the user through
cookies when he comes back to the site, then you
search for the credentials in your
database and
sign the requests that will do the
retweets with this unique, individual
credentials.
Retweets are supported by a different API, the
REST API. This framework is for the Streaming API, which has nothing to do with retweets. I'm afraid to tell you're in the wrong path for what you're trying to do. I suggest you go for
Abraham's Twitter Oauth library for PHP, wich uses the
REST API that supports
retweeting.
REST API resource for retweets:
https://dev.twitter.com/docs/api/1.1/get/statuses/retweets/%3AidAbraham's PHP Library to support OAuth for Twitter's REST API (this library is recommended by
Twitter):
https://github.com/abraham/twitteroauth