Tweaks

• More paypal changes. C9 would incorrectly include 'completed' order and 'fee reversal' txns in its attempt to compute how much paypal reports is captured so far (since paypal doesn't provide this directly). Would result in incorrect computation, particularly with very old backorder finalisation an inattentive operator could inadvertently refund the entire sale when clicking through defaults.
• Added new income GL code for government subsidies / payments
• Bugfix with clearing surcharge lines  on unit deals. A surcharge line (persisted by rolling back a  straight sale into a deal which had a surcharge) would crash c9 and not allow you to refinalise the deal until the surcharge line is manually deleted. Now fixed.