Physics rework, v8.3b

Reworked physics for ETS2/ATS.


Recommended settings (can be changed in console or in config files):

g_cam_physics_value "1.0" (DEFAULT)
g_cam_physics "1" (DEFAULT)

g_cabin_suspension_stiffness "1.3"
g_suspension_stiffness "0.3"
g_trailer_stability "0.5" (DEFAULT)
g_truck_stability "0.3"

g_brake_intensity "1.0" (DEFAULT)

residual_travel[] in chassis defs - 0.10 and 0.088 (DEFAULT)

ATTENTION!
If you move the cabin suspension slider in the game's config, the parameter g_cabin_suspension_stiffness cannot become 1.3 again! Then you have to set it to 1.3 manually (in the console or in the profile's config.cfg file)!