Issue 2497 refactor to idp

Background for pull request: Issue https://github.com/mozilla/browserid/issues/2497#issuecomment-26439900

Creating a pull request to try to get some frontend help.

Thanks to @shane-tomlinson for previously reviewing and getting it this far.

Known Issues:
* siteName and other options aren't passed in from Desktop code, I'm investigating in gecko

Needs Frontend <3
* rpinfo changes in dev broke this patch, minimal hardcoded changes were made to get it working again
  * Need help doing this correctly