get_visible
Description:
Checks if the connection is visible to the current user.
 If the connection is not visible then it is essentially useless; it will not contain any settings, and operations such as 
      save and 
        @delete will always fail. (NMRemoteSettingss will not normally return non-visible connections to callers, but it is possible 
      for a connection's visibility to change after you already have a reference to it.)
Parameters:
| this | the RemoteConnection | 
Returns:
| true if the remote connection is visible to the current user, false if not. |