Rewrite IETF ID URLs to Tools or Datatracker

This will rewrite the "official" IETF Internet Draft URLs (http://www.ietf.org/id/foo-42.txt) to the Tools (http://tools.ietf.org/html/foo-42) or Datatracker (http://datatracker.ietf.org/docs/foo) versions instead.

This uses Google Analytics to track how many folk install / use the extension (so I know if it is worth putting time into updating it, etc. If this offends you, let me know and I'll send you a version without the tracking stuff).

Version log:
1.0.4.0:
-- Added checkbox to redirect to SSL sites (enabled by default)
-- Code cleanup.

1.0.3.1:
-- Fixed option saving issue (Content-Security-Policy was not allowing inline event. Moved options code to its own file (options.js))

-- Updated to use Version 2 manifests.
-- Update with patch from Barry Leiba to handle https and "rfc-editor.org"