Up until now, services developed (sms) relied on the get() and
InsufficientCreditError mecanism to create iap_accounts on the fly and
recharge it.
This particular workflow does not work well with automated processes which
is why we modify the function get_credit_url such that it will allow the
client to generate the 'recharge' link manually for better integration
of iap services.
Rémi Rahir
af2f12b136