Little improvements for beta for quit-applet-plus

Little improvements/extensions: - add a title icon to all dialogs - add the option "Show menu icons" - add the option "Show 'Standby' action" - add the button "Simulate Ctrl+Alt+Delete" to the testing dialog

Option "Show switch user item" for quit-applet-plus

switch user item should be only shown if its option is selected. It should be preselected by default, but you can deactivate it if you don't need it.

Time delayed automatical quit for quit-applet-plus

As an option, if selected, after a few seconds (should be configurable) the "Shut Down" action should be performed automatically after starting of the "Quit..." dialog. The countdown should be shown as progress bar or something else, but in every case graphically.

German translation for quit-applet-plus

German translation in order to include the german ubuntu community for alpha 2 testing (as I live in Germany).

Show all quit actions directly as an option for quit-applet-plus

All actions should be shown directly in the popup menu without the quit dialog if this option is selected.