Hook up alarm dialog for sunbird. bug 299366, patch by jminta, r=mvl

calendar/locales/en-US/chrome/calendar/calendar.properties

@@ -109,6 +109,7 @@ defaultPreviousWeeksInView=0
 showAlarms=1
 showMissed=1
 playAlarmSound=0
+soundURL = chrome://content/calendar/sound.wav
 reloadServersOnLaunch=false
 defaultEventLength=60
 defaultSnoozeAlarmLength=60