fix potential crash bug when server returns no collection members
Fix "can't edit contact" / "account doesn't show up" and other bugs; refactoring

* support for phonetic names (closes #19)
* update contacts.xml, tested with 4.0 (Samsung), 4.2 (Cyanogen), 4.3 (Cyanogen) (fixes #5, fixes #6, fixes #7)
* smarter error handling (1): notify sync manager in case of HTTP auth errors
* smarter error handling (2): just ignore the dubious resources instead of notifying Android sync service
* refactoring: created DavSyncAdapter and move common code to it
* version bump to 0.3.4-alpha