[Lazarus] Purpose of TShellTreeView.ShowRoot

[Sven Barth]

Hello together!

I'm currently testing around on the TShell* controls and came to the 
ShowRoot property now.

1. Why is this property duplicated in Options as well?
2. What's the purpose of this property? I personally thought that it 
would allow me to show/hide the root node (e.g. on Linux "/" by default 
or the root set in the "Root" property), but changing it to "false" just 
hides all extend signs in the tree (and thus the subdirectories can no 
longer be extended).

Regards,
Sven