Handle boolean values.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12499 e27351fd-9f3e-4f54-a53b-843176b1656c
First pass at who extensions


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@12500 e27351fd-9f3e-4f54-a53b-843176b1656c