* Added non-zero default values to InventoryOrder constructor
* Had to redo chunks of DatabaseManagerInventoryOrder as it didn't work or match what was in the DB
* More work done on EnterEditOrderForm
* Finished initial implementation of PurchaseInventoryRequest
* Added a button for logging Inv requests to EnterEditInventoryForm. Should probably add the functionality to the SearchInventoryDialog as well, to ease the user's workflow