* src/commands.c (cmd_ppcheckout): Add some code for recurring
donations.
* src/paypal.c (status_unauthorized_seen): New flag.
(call_paypal): Improve debugging code.  Set that new flag.  Add arg
REQ_METHOD and change callers to provide that.
(get_access_token): Flush cache after a 401 was seen.
(find_plan): New.
(paypal_find_create_plan): New.
* src/t-util.c (test_convert_amount): Add garbage tests.