Command to Logout / Shutdown / Restart KDE4

There may be another easier way to do this, but this command will bring up a dialog box with the options to Logout / Restart or Shutdown KDE4.

qdbus org.kde.ksmserver /KSMServer org.kde.KSMServerInterface.logout 1 -1 -1

This is useful for when Plasma crashes and will not restart. (I actually have no idea how to manually restart plasma.)