Remove display unit storage in class and resource bundle

[averbraeck]

At the moment, all display units are stored in the quantity's unit class:

    public static final SpeedUnit KM_PER_HOUR = SI.deriveLinear(factorLD(LengthUnit.KILOMETER, 
            DurationUnit.HOUR), "km/h", "kilometer per hour", UnitSystem.SI_ACCEPTED, 
            "km/h", "km/h", "km/hr", "km/hour");

while the same information about the display units is also available in the language resource bundle:

Speed.km/h = km/h | kilometer per hour | km/hr | km/hour

For maintainability and flexibility uses, this information should be stored in only one place, preferably the resource bundle, since that information is now used to parse Locale-dependent input. This makes storage in the class superfluous.