Fixup Register Login Sample, add getPicture:Size

RegisterLogin had a bunch of issues, including not compiling.

Fixed it up so that it followed iOS conventions: use the navigation bar instead of "back"/"save" buttons, etc.

Cleaned up layout so it fits in iPhone 4 sized screens.
I believe the breaking compilation we had here was intentional (I believe based on an earlier conversation). Either way, I think we don't want to commit app keys/id's, right?