Accept Paypal button URLs instead of forms

[balupton]

When creating a paypal donation form/button, you have the option to get it as an email link, this will reveal a nice url like:

https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=QB8GQPZAH84N6

This is the only thing that we should ask for as it is a lot easier to add.

[fmay]

Good idea.