This commit includes the major changes between DAVdroid and EteSync. It
adjusts the app to use the EteSync protocol and server. It includes some
ugliness still, and it's a squash of many ugly snapshot commits while
hacking on the initial DAVdroid code.
History should be "clean" from this point onwards.
* rewritten contact group support to support VCard3 CATEGORIES and VCard4-style KIND/MEMBER groups
* new account setting: contact group method (VCard3/VCard4/Apple "VCard4-as-VCard3")
* keep unknown properties when saving/generating VCards
* new setting: only sync in WiFi (or when sync is triggered manually)
* new setting: only sync in specific WiFI (by SSID)
* lower default sync interval when account is created to 4 hours (was 1 day)
* version bump to 1.0.6
* add InvalidAccountException for invalid (=not existent/invalid settings version) accounts
* handle invalid accounts properly
* HttpClient: add constructors without Account when authentication is not needed
* drop upgrade compatibility for accounts without version (version<1)
* add account setting + GUI: restrict time range in the past
* add support for restricted time range VEVENT synchronization
* fix bug in handling changed exceptions of recurring events
* CalendarSyncManager/TaskSyncManager: only set calendar name and color on sync when data is available
* DavResourceFinder: test getCurrentUserPrincipal
* dav4android: use java.util.ServiceLoader, resilience against multi-status with <propstat> without <status> + test
* ical4android: always set HAS_ATTENDEE_DATA to 1
* vcard4android: small fixes
* merge translations from Transifex
* ical4android: treat empty-string task location and URL as null values
* vcard4android: ignore raw contact data without MIMETYPE
* gracefully ignore when server doesn't sent Content-Type in GET responses
* merge translations from Transifex
* Contacts sync: if REPORT addressbook-query doesn't work, don't ignore other exceptions than HTTP 40x errors
* dav4android: Digest auth improvements (e.g. for OS X Calendar Server)
* vcard4android: better support for exotic IMPP handles and names
* use ExternalFileLogger to log synchronization, if enabled in Settings
* new settings: log to external file / log verbose
* DavResource: check for well-known even if service type of user-given URL can't be determined
* remove oblsete testing assets
* allow cancellation of synchronization within appropriate time
* sync error notification: use loader, show all accounts, show whether JB Workaround is installed, reorder
* move address book settings from account user data to ContactsContract.SyncState
* remove "VCard4 capable?" setting (as it's detected at every sync)
* show user notification when updating settings version or when Android version was increased
* improve stack trace in DebugInfoActivity
* get rid of Guava (use Commons again)
