* Bug fix in API forms
- Allow form fields to specify custom filters at runtime
* Add "contact" model to purchase order edit form
* Add action to create new purchase order from list widget
* widget updates for purchase order
* Adds a helper function for rendering currency data
* Update helper functions for StockItem model
* Render purchasePrice correctly for stockitem
* Use currency_formatter library instead of money_formatter
* Add total price display for purchase order
* icon fix