Add installcheck_script based on Graham Gilbert's here: https://github.c...

...om/grahamgilbert/mactech_2014/blob/master/Profile/installcheck_script_v2.sh

This change adds an installcheck_script to the Munki pkginfo based on Graham Gilbert's work. The effect is that if the profile is removed (via the Profiles preferences pane or the /usr/bin/profiles command), Munki will detect this and reinstall the profile.