Updated dropbox handling to deal with some client edge cases. Also fix up some authorization issues.
Updated dropbox handling to deal with some client edge cases. Also fix up some authorization issues.

git-svn-id: 0c33e958600270102f91bf5868e396345dde476c@6649 e27351fd-9f3e-4f54-a53b-843176b1656c

red-hood/calendarserver,red-hood/calendarserver,red-hood/calendarserver,red-hood/calendarserver,red-hood/calendarserver,red-hood/calendarserver