Update SabreDAV to 1.8.10

requires https://github.com/owncloud/3rdparty/pull/95

calendar: https://github.com/owncloud/calendar/pull/431
contacts: https://github.com/owncloud/contacts/pull/501


TODO:
- [x] announce that change on the dev ml - http://mailman.owncloud.org/pipermail/devel/2014-May/000248.html
- [x] test file sync (t1.pl, t2.pl, t3.pl and t4.pl have been executed successful)
- [x] test with litmus
- [ ] test caldav sync
- [ ] test carddav sync