Issue #2625142 by felribeiro, quietone, tstoeckler, cilefen, Arla, jhodgdon,...
Issue #2625142 by felribeiro, quietone, tstoeckler, cilefen, Arla, jhodgdon, smustgrave, Berdir: Document that Uuid::isValid() only considers lowercase UUIDs as valid
(cherry picked from commit b8dc375a)