Fixes for cross-pod proxy support.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@14083 e27351fd-9f3e-4f54-a53b-843176b1656c
Cross-pod proxy support. Still needs work to better handle errors and improve performance.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@14084 e27351fd-9f3e-4f54-a53b-843176b1656c