Command line when already running

If kodi.exe is launched with a song or playlist on the command line, it does not play if Kodi is already open.  This makes Kodi incompatible with all playlister and remote control software.  Kodi must be terminated before it will obey the command line and play something new.  Please consider adding this ability.  In Windows, the easiest method might be using GlobalAddAtom() to create a global ATOM which can be passed to another process using WM_COMMAND.