Pre-flight the APNS certificates, and the EnableCalDAV/EnableCardDAV values.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@13967 e27351fd-9f3e-4f54-a53b-843176b1656c
testserver now creates a "sandbox" for CDT to run the calendar server in (and also starts/stops the server)


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@13968 e27351fd-9f3e-4f54-a53b-843176b1656c