Refactor and inital modelbuilder and exporter classes.
fixed null cellsize
fixed exporter xml generation
Remved unused cursor
Merge branch 'master' into new-cell

Conflicts:
	src/App.mxml
	src/org/cordis/arritmias/ui/CellGridRenderer.as
Fixed model reset.
Fixed Square an circle drawing.
Removed useless method
Added improved sensor logic
Fixed renderer not drawing after reset.
Added cells export to model exporter