Summary:
- wrap entire managedsoftwareupdate execution and kill if open for 12 hours.
- move "delay/sleep" logic into supervisor, removing need for updatecheckhelper (but keep updatecheckhelper around so clients continue to work without reloading launchd)
git-svn-id: http://munki.googlecode.com/svn/trunk@1115 a4e17f2e-e282-11dd-95e1-755cbddbdd66