Is art bug fixed PP button code fleshed out

There was a bug where is_art wasn't being updated if it was changed from
true to false.
PP button search code works, working on button creation and storage.
Adding actual paypal code to the plugin

Code for finding, creating and updating paypal buttons added. No testing
done yet.
Using GetDetails instead of Search, error catching

The search function doesn't return much information about the button and
a large amount had to be hard coded. In comes GetDetails and its magical
all-retrieving gifts of the gods.
Also added some catching code to make sure the button exists and that
the creation was a success before setting any meta data.