* Refs #99 -- Fix stripe support for zero-decimal currencies
* Add new money formatting method
* Force decimal places in many places
* Locale-aware currency rendering
* Fix currencies in more places
* More currency fixes
* [WIP] Failed Payment error handling
When finished, this should fix#248
* rename PaymentFailedException to PaymentException\nimported Exception where neccessary
* comments fixed
* minor style fixes
* Fixed a name error