AKScheduling: Make tracks on track manager page resortable

added feature label

changed milestone to %KIF 51,5

Instead of lists on a fixed grid, maybe use free-placeable "windows" for the lists

changed milestone to %KIF 52,0

assigned to @bhaettasch

mentioned in commit 1185c608

mentioned in merge request !218 (merged)

mentioned in commit a5d06dc7

mentioned in commit 85f51eaf

closed with commit a5d06dc7

closed with merge request !218 (merged)