added use of DistribVegDlg, fixed Layer Flatten to not delete layers that could not be merged
added use of DistribVegDlg, fixed Layer Flatten to not delete layers that could not be merged

markraz/vtp,nakijun/vtp,seanisom/vtp,markraz/vtp,nakijun/vtp,markraz/vtp,seanisom/vtp,markraz/vtp,nakijun/vtp,seanisom/vtp,markraz/vtp,nakijun/vtp,nakijun/vtp,seanisom/vtp,seanisom/vtp