Used KeyAdapter instead of AbstractKeyListener
Added items toolbar to Sales Requisition panel
1. Moved total fields to the right for Sales Requisition/Invoice panels
2. Added double-click behavior in Sales Invoice list panel
Added discount property to Supplier model
1. Changed Order icon in Purchase Order panel
2. Disabled Post button in Purchase Order panel when not yet applicable
Updated initial product data to include unit conversion details
Updated version to 0.9.2