Optional implicit ratio conversion and unified ratio handling when dividing and multiplying
Changes since previous versions:
- Implicit / automatic conversions between units of different ratio can be disabled with the preprocessor flag DISABLE_IMPLICIT_RATIO_CONVERSIONFixed division of units with same exponent so it considers ratio
- Bugfix in division of units with different exponent and different ratios
- Multiplying units with different ratios results in mutiplied ratios instead of gcd of ratios squared
- Added division of units by a scalar
- Scaffolding for testing intentional compilation failure