The TreeView has an important feature in which right-clicking in the space
around the tree nodes causes the context menu of the hidden root node to appear.
We utilize this feature in the EntPack and rely on it.
Unfortunately, the ListView lacks this feature. Basically two things need to happen:
1. ListView.PopupSupport.showPopup(MouseEvent) needs to not change the selected
index if the mouse location is outside of the bounds of any list item (i.e. if
contextMenu were true).
2. ListView.createPopup() should set the hidden root node as the selected node
if the contextMenu parameter is true (in order for the context menu actions to
have the appropriate context).
Reassigning to new module owner Tomas Holy.
Provide patch, if you want this.