Use javax.measure?

[jboynes]

See https://github.com/unitsofmeasurement

JSR 363 added "official" support for Units of Measure. JSR 385 extends that to account for the SI revision expected in 2019 as well as updating the API for modularity (Java 9 and later).

The Unit class has a "todo" to reexamine units once JSR 363 goes mainstream. Even if we don't we should decide which units we should support, especially ones related to computing systems.