Changes

New attribute '''air_pressureair_tank_pressure''' now defines nominal pressure truck wants to keep in air tanks. Default value is 10 bars.

With more exact simulation of air pressure we unified animation API. All animation now expect values in bars. To prevent misunderstanding they were also renamed (with their '''_max''' and '''_min''' values): '''oil_psi_anim''' to '''oil_pressure_anim''', '''air_psi_anim''' to '''air_pressure_anim''', '''button_low_air_psi''' to '''indicator_low_air_pressure''', '''button_low_oil_psi''' to '''indicator_low_oil_pressure'''.In addition animation '''brake_psi_anim''' was renamed to '''brake_pressure_anim''', and is not in range 0-1 of brake limit anymore, it uses bars like all other pressure animations instead.