New Sleeper Coaches

[EmperorJake]

Two new sleeper coach types:

"Trans Euro Night" Sleeper
Intro date: 1970
Capacity: 50
Speed: 140km/h
Regions: Europe

"CityNightLine" Sleeper
Intro date: 1995
Capacity: 60
Speed: 160km/h
Regions: Europe

edit: Due to the asymmetry of some of these, you could make them build randomly flipped to create more visual variety.

[EmperorJake]

You can add reverse_build_probability: return 50; to the graphics block to make them randomly flipped.

Also keep the issues open, I'll probably dump more graphics later :)