Oops. Forgot to pass a null for NSAction parameter.
Added CropMode enum for ProfilePicture Control.

ProfilePicture is being added, required by GraphUser, required by
LoginButton.
Removed irrelevant non-Xamarin code.

This file is not a project link to the original winclient-sdk lib, so
we don't need conditional compilation to stay compatible.
Minor oops: missing "this".
Finished Controls/ProfilePicture initial implementation (theoretic).