Determines if Rhino is currently running a command. Because Rhino allow for transparent commands
(commands that can be run from inside of other commands), this method returns the total ids of
RhinoCommon (in RhinoCommon.dll)
public static Guid GetCommandStack()
Public Shared Function GetCommandStack As Guid()
Ids of running commands or null if no commands are currently running.
The "active" command is at the end of this list.