Issue 431: make methodology clear
Taking into account the discussion in the crm-sig list about Place vs. SpaceTimeVolume, Martin proposes to add in the CRM, in the section Terminology, definition of "Class", to add an adequate variant of
"It is per definitionem wrong for all CRM concept to argue with the meaning of the label. Labels can only be wrong wrt to the scope note. Per definitionem they do not constitute definitions."