(svn r9844) -Codechange: replace zoomlevel with an enum
-Codechange: use predefined enums for viewport zoomlevels

(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. :)

(svn r8338) -Codechange: merged road vehicle build window into the other ones
Note: now all build vehicle windows are merged into build_vehicle_gui.cpp

(svn r8128) -Codechange: Split sprite and palette remap into separate 32 bit values.
This lets us increase the sprite width from 14 to up to 29 bits,
effectively nulling the old sprite limit. Table changes in next commit.