Fix the Oauth code so that it generates signatures correctly. Logic
taken from https://github.com/moshbit/paypal_permissions and modified to
fix issue with coverting dots and dashes to entities but the case not
matching what Paypal expects.
Fix basic_personal_data so that it sends the X-PAYPAL-AUTHORIZATION
header so it returns the data for the actual paypal account assigned to
the token rather than the parent account
Remove unused constants