(svn r8978) -Feature: Rewrite of transfer system.

This major feature-fix keeps track of the value of transfers offloaded at a station, and hands on to a loading vehicle a credit note proportionate to the cargo loaded. The transferring vehicle is paid only for the distance it has travelled. eg. B-C in a transfer chain A-B-C-D.
When the final cargo is delivered, these credit notes are cashed, and the final vehicle is paid for A-D minus any credit notes it is carrying. The company bank balance increases by the value of the A-D route.
You still need to set up a profitable route; it is still easy to make a loss on transfers by bad planning. :)

src/lang/english.txt

@@ -3143,3 +3143,5 @@ STR_DATE_SHORT                                                  :{STRING} {NUM}
 STR_DATE_LONG                                                   :{STRING} {STRING} {NUM}
 
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+
+STR_FEEDER_CARGO_VALUE                                          :{BLACK}Transfer Credits: {LTBLUE}{CURRENCY}