Add Normalisation

[atmoos]

Add a Normalise(): String method.

Scenario: Say you have a length instance of 78'167 μm. This is an unwieldy representation for humans to read. More natural forms of the same length would be 78.167 mm or 7.817 cm, where the latter value has been rounded.

Tasks:

• Find a good name for that method ("Normalised", "DisplayValue", "HumanReadable", etc. could be other names)
• Decide whether the value should or should not be rounded to max. three digits
• Find an implementation that efficiently computes the normalization for values in the metric system
• For the imperial system decide whether:
  • To not implement this functionality
  • To convert the value to a metric value that can be normalised
  • To convert the value to the "best" representation within the same system (This may open up a can of worms...)

Note also the example in the readme: 3'456 Km/d => 40 m/s

• Is that a good normalization? (people are more used to Km/h)
• Compound Quantities will be hard to reasonably normalise...