Add LatLongCalculator

I give up. I tried to come up with a public `equals` that just works but it's hard. Values about 360° need a few bits of precision before the comma. Values about 0° can use these bits for additional decimal places after the comma. Always rounding these decimal places away (basically applying `round( ..., 13 )`) doesn't make much sense. Why lose precision if it's there?

I dropped half of the code I wrote.

To make this clear: We are _never loosing_ precision. We are _gaining_ precision. But the additional decimal places are pointless.
This is just a normalizer. Why is it called "calculator"? If we want to add methods for comparing and combining, I suggest to call this "GeoMath".