Update to Drupal 7

Here is an initial attempt at updating this module to Drupal 7 now that the pay module has a 7.x-1.x-dev version.

There are still some bugs in the pay module the need to be fixed in order for this to work 100%.

The following three patches are needed in order to get the donate module to work at all.

#1333740: DBTNGify query in pay.admin.inc / pay_admin_pay_form_list().
#1333750: Bad parameters for count() function in pay_form.inc
#1333752: &$form parameter missing from pay_form_settings and pay_form

And ... it appears that there is something wrong with the pay module that prevents payments from the donate module actually being fully collected. The transaction is created but the $$ is never collected. Probably an issue with the custom pay formatter. Though, that's why donate needs to be updated, so we can find problems like this. :)