Use CopyMode to control the operation when an item is dragged or dropped.
property CopyMode: TJamDropEffect;
DEPRECATED: Use AllowedDragEffects and AllowedDropEffects instead.
The CopyMode will influence both received and sent drag operations. Received drag operations can be additionally controlled by TJamShellList.OnShellDragOver
oMeisberger -cV11.1: Remove getter of deprecated property CopyMode