Provides support for parsing and formatting string unit specification, converting numerical values between compatible units, and performing arithmetic on units (such as dividing one unit by another).

## Examples of Intended Use

The following code will print the string`"5 knots is 2.57222 m/s"`:

> `UnitFormat format = UnitFormatManager.instance();`
> `Unit meter = format.parse("meter");`
> `Unit second = format.parse("second");`
> `Unit meterPerSecondUnit = meter.divideBy(second);`
> `Unit knot = format.parse("knot");`
> `if (meterPerSecondUnit.isCompatible(knot) {`
> `System.out.println("5 knots is " +`
> `knot.convertTo(5, meterPerSecondUnit) +`
> `' ' + format.format(meterPerSecondUnit));`
> `}`
> ``