Bring back a few required tweaks for OpenSSL and OpenSSL builds that allow us to succeed on Linux


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@13467 e27351fd-9f3e-4f54-a53b-843176b1656c
Refactor the way unit tests create stores and directories; unit test directory records now come from txdav/common/datastore/test/accounts/*xml; also ServersDB is not a global, but instead lives in the directory service.


git-svn-id: https://svn.calendarserver.org/repository/calendarserver@13468 e27351fd-9f3e-4f54-a53b-843176b1656c