1.7 - add necessary images for track building 1000mm / 5.5m catenary

1.6
- Steam release

1.5
- Remove requirement to load CommonAPI2 modular station adapter (note for build < 29112 it is still required!)
- Change min radius and slope values for 750mm tracks
- add code to hide old module system (removes duplicate tracks in stations in build >= 29112)
- change images to be compatible with build >= 29112