A number of bug fixes related to recent release

• General Ledger fixes
  • Was failing to write no cash collected type sales under some circumstances now.
  • Following invoice scenario would not write/save.  Refunded spares + an order + deposits on order where total deposited > refund
  • Changing instrument on existing activity record
  • Taking payment on previous no cash collected activity item
• Very serious problem with receive order if you select to receive an order with no parts (i.e. freight only) the system would potentially SMS a huge number of unrelated customers based on parts ordered years previously.