Updating Facebook Module to use new permission 

Updated module to use a new permission when attempting to post to the OpenGraph ( changing publish_stream to publish_actions )

See https://developers.facebook.com/blog/post/2012/04/25/streamlining-publish_stream-and-publish_actions-permissions/ for more details
Merge pull request #83 from davefreeman/master

Updating Facebook Module to use new permission