Useful to remember max payload

Signed-off-by: Milko <Beppe@giuseppe.(none)>
FIX: Correct payload for experimental
FIX: Some incorrect payload for post version
ADD: "Feltham" type tram (awaiting finished graphics)
CHANGE: Update .dat file for Balloon tram ready for rescaled graphics and multiple liveries
ADD: Bombardier Flexity 2 tram (awaiting completed graphics)
ADD: Some experimental player colours on some depot types (mainly W. Lindley)
CHANGE: All depots now have player colour plaques
CHANGE: Reduce cost of building boatyards
ADD: Blackpool EE Railcoach (awaiting finished graphics)
CHANGE: Add a few street/stop names
CHANGE: Rescale Sheffield Supertram (awaiting final grahics)
Merge branch 'Payload' of https://github.com/Milkogit/simutrans-pak128.britain.git
ADD: Processed graphics for new and revised trams
ADD: Processed graphics for new and revised LBSCR locomotives