Returns unique ID for the user since server started.
A Long value.
The UID Property syntax has these parts:
evaluating to an object of type FtpUser.
UID property holds unique ID for the user - value that
will never change (unlike Index property!) as long as user
is connected. Each user that connects during server's
lifetime (until wodFTPD.Stop method is called)
will have his own UID.
You can store this UID information in your program, and
can access this user later on using wodFTPD.Users.UIDs(useruid)