Fixed "already contains a definition" when running __UnitClasses.tt on a clean checkout. Commented out include even though once="true" should prevent this from happening.
Added __TestClasses.tt that generates an abstract unit test template class for each unit class.
Renamed protected abstract double OneXXXInYYY to YYYInOneXXX prop getter.
Disable build warning CS1718: Comparison made to same variable; did you mean to compare something else?
Re-implemented LengthTests.cs using generated LengthTestsBase.
Renamed generated test base class filenames to plural, to match class names.
Reimplemented AngleTests using base class. Gradians test is failing, most likely due to bug in implementation.
Made Delta property virtual instead of abstract, so overriding it is optional.
Added remaining unit class tests using base class. Some tests are still failing.
Fixed unit tests and implementation.
VolumeTests.cs had bad constants, implementation OK.
Unit.cs had bad constants for angle radians and gradians, so effectively a bad implementation. Tests were OK.