FoilLogic & refactor fin -> foil
Foil class
Path init in Foil
Paths owned by Foil
PathItem not a QGraphicsItem
Refactored Path from EditablePath
Memory leak according to Valgrind
Contour calculation -> foillogic
foilCalculated signal
Area calculation -> FoilCalculator
Grid-adaptation connected
fastCalc
Refactoring calculation logic into foillogic