Alpha Trolleybus Skoda 14Tr 2.1

- diesel/lpg bus variant 14Ab (fictional, inspired by the look of Karosa B734/B934), police and firefighter variants with lightbar and siren, two different engines (LiAZ V12, V12 Turbo and V12 LPG)
- added rear and front license plates (different positions for 14Ab and 14Tr)
- removed unit numbers
- edited glow maps
- bus mode is now working
- added bus displays (destination signs)

- US-like and UA-like livery
- service unit (with working beacons)
- added second diesel trailer (yellow with beacon)
- added trolleybus train unit (Skoda TV - 14Tr). Basically just a 14Tr with tow bar which can compose trolleybus train by using them as trailer. LUA scripting for steering as "сцепка" (working just on the first trailer unit, the other ones copy the same).

Added two new liveries

Trying to make it working with bus mode, unfortunately still not working.

Added airbags and shocks to suspensions.
Radiator fan driven by LUA script.
3 different radiator fans for sound effect.
Files cleanup.

- Added electric power generator trailer with diesel engine

Configurations tweaked