WIP: Modernize Relations
- add defaulted virtual destructors to BaseRange and BaseTable
- prefer STL algorithms over raw loops
- use std::sort instead of std::stable_sort given that the result is passed through std::unique which removes duplicates
- remove SVN/CVS keywords
- prefer implicit destructors over trivial explicit destructors
- do not call member data default constructors in constructors
- prefer DeclareInterfaceID