Remove included library

Changed the Persona library include into documentation to include the script in templates until Meteor has the ability to specify remote javascript to include. This makes the smart package less critical to keep up to date with Mozilla changes.

I'm not really sure this should be the normal approach. So I don't know if you should actually accept this pull request. I'm sending it because it's better for my project but it may be best to leave it as a pull request so people can fork and pull it rather than make it the standard choice?