Shipping option 2 prompts the buyer for an address, and requires one before
payment is taken. PayPal 'rm' variable specifies the return FORM method used
upon success payment:

 Allowable values are:
  0 . all shopping cart payments use the GET method
  1 . the buyer.s browser is redirected to the return URL by using the GET method, but no payment variables are included
  2 . the buyer.s browser is redirected to the return URL by using the POST method, and all payment variables are included

 The default is 0. Note: The rm variable takes effect only if the return variable is set.

…e_url' header image support to form.

The method `<PayPalPaymentForm>.render_as_GET_url()` and it's sandbox version can be used
to directly redirect to PayPal payment page from view that performs pre-payment processing;
for example a view that check if shipping information was entered and is correct, to confirming
that inventory is still adequate for order. Readme documentation was updated to reflect these changes.

For example in Eclipse one can enable "Show whitespace characters" which helps with code blocks and for this tabs are a better choice than spaces. Another plus once can easily specify 'tab' character visual length which you can't do for spaces; hence this developer uses tabs against 'PEP-8' strong recommendations.