Spare parts complete : new option to merge parts on order onto an existing order.  Provides a mechanism to add further parts. Stocked parts on part list will be transferred into reserve/layby segments when this option is selected, so it is used purely to add things to customers order/pickup list only.

Fixed a serious defect that only occurs under rare intermittent network situations, i.e. where network is okay during some initialisation stages when c9 opens, but then network drops out during later steps in initialization process, but the failure is silent and doesn't cause any obvious problems during loading of c9. Typically talking about a window of failure of a few milliseconds only but if it does trigger system does all sorts of weird stuff like not writing invoices correctly.