QUDT Release v2.1.39

Apologies! Release v2.1.39 was published before I hit 'git push' on the updated schema and vocabulary files, so they still contained the earlier release number in the metadata. This is the re-release of v2.1.39 with the correct metadata.

Updates include:

• Added quantitykind:StrainEnergyReleaseRate supporting mechanical fracture (thanks @mgberg)
• @berrisfordjohn was very productive rooting out errors this month. Thanks for all your efforts @berrisfordjohn!
  • unit labels
  • the descriptions distinguishing GibiBIT-related and GigaBIT-related units
  • ampere per square second distinct from ampere squared per second
  • replacing some non-ascii hyphens with ascii hyphens
  • correcting the quantity kinds and language tags for unit:GM-PER-CentiM-BAR and unit:GM-PER-MilliM-BAR
  • removing erroneous plurals from several labels
  • correcting a number of incorrect symbols
• Prompted by @glow-mdsol, we now have a systematic approach for handling "equivalent chemistry" units, still found in biochemistry. The key is not to define new units, but rather new quantity kinds. This is discussed here.
• We cleaned up the skos:broader hierarchy for SpecificEnergy so that relevant values of applicableUnits are generated by our algorithm.

And as always, a big thank-you to all of you for bringing many of these issues to our attention, and even better, for providing submissions to extend the coverage and capabilities of QUDT!