* [TD] remove unused headers
- also some sorting
- also improve readability by not using an abbreviation (we consistently don't abbreviate class names)
- correct interpretation of True vs Projected
- handle long subelement names in references
- fix "too small" value condition
- better error messages for bad dimension geometry
- separate validation, geometry and reference handling into
individual files
- improve 3d reference geometry handling
- eliminate duplicate dim creation code
- add Dimension reference repair dialog
- Refactor formatting out of DrawViewDimension
- move dimension repaint control to ViewProvider
