Now passing oauth_callback via Authorize header instead of GET
Making scope optional and a little easier to shut off
oauth_verifier no longer needs to be sent via GET.

It is, however, automatically read from the current script executions GET request, and added to the
Access Token request thanks to the PHP OAuth class. So, it's still there, we're just not manually adding
it to the outgoing GET request anymore.
Making tool easier to use
Specify permissions from index page