Validate sale order IDs upon entry.
Display errors when grabbing Endicia/USPS account balance fails.
Fill in a default value for shipper ID.
Bugfix: Update broken reference to View.getBoxCode.
Preload package dimensions.
Bugfix: Use getSaleOrderID properly.
Call new initialization functions. (initShipperID and preloadPackageDimensions.)
Rename activate and deactivate functions to be more descriptive.