This adds basic guest control commands to the "Machine" menu - a nice
added-value for the GTK UI.
We use "pause" as the term for stopping the machine here. So reword also
the related caption tag.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>