Fixed showing speed inside vehicles with multiple seats (WAC, simfphys, etc.).

Small fix

You can now choose when to show the HUD: only when you are in vehicle, only when you are not, or both.

To implement this functionality, the old settings have been extended.
Variable vrad_speed_enabled has been replaced by two: vrad_speed_enabled_player & vrad_speed_enabled_vehicle. This means we have four configurations now.

Fixed an occasional error when you leave a vehicle

Cosmetic fixes.

Added "Hide in vehicles" option (experimental).
Some small improvements.

Added "Horizontal velocity" option and its respective ConVar - vrad_speed_horizontal.
Fixed "Enabled" setting.

Some visibility fixes.