Util.killall: add utility for killing unwanted processes

Since we have to use pkill, kludgily, for the right combination of
portability and featurefulness, put the code in one place rather than
duplicating it everywhere.

https://bugzilla.gnome.org/show_bug.cgi?id=635089

js/ui/statusIconDispatcher.js

@@ -6,6 +6,7 @@ const Signals = imports.signals;
 
 const MessageTray = imports.ui.messageTray;
 const NotificationDaemon = imports.ui.notificationDaemon;
+const Util = imports.misc.util;
 
 const STANDARD_TRAY_ICON_IMPLEMENTATIONS = {
     'bluetooth-applet': 'bluetooth',
@@ -33,8 +34,7 @@ StatusIconDispatcher.prototype = {
         // app-indicators, so that applications fall back to normal
         // status icons
         // http://bugzilla.gnome.org/show_bug.cgi=id=621382
-        let p = new Shell.Process({ args: ['pkill', '-f', '^([^ ]*/)?indicator-application-service$']});
-        p.run();
+        Util.killall('indicator-application-service');
     },
 
     _onTrayIconAdded: function(o, icon) {