- fix dialog layout (was broken for Windows) and simplify it
- enable so immediately the changes you make in the dialog -> necessary to fine-tune the right position
- make TileColumn read-only
- restrict TileRow to what is possible
- improve tooltips
- add button to flip the sides (the symbol is not mirrored, just flipped)
- replace use uniformly Gui::QuantitySpinBox
- fix and uniform size of all objects in the dialog
- apply changes immediately once the section is created because this speeds up the workflow a lot, especially for when changing the plane position
- some code cleanup: remove unused void, avoid unused variables