Import CAD popup message

This is not an actual tool. It is a popup message that will warn the user when he is trying to Import CAD. It does not prevent the user, it just warns him, so after clicking OK it launches the usual Import CAD dialogue.

We all know about the bad practice of importing CAD files instead of linking them... well, unfortunately not every user knows, so I thought that I could avoid some CAD imports within my team if Revit warns the user about it.... better than nothing!