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.
* change group methods to less specific values
* new account settings version: change group method to CATEGORIES for updated accounts
* change group method from CATEGORIES to GROUP_VCARDS automatically when a group VCard is received
GUI:
* AccountSettings: disable CalDAV/CardDAV options when the corresponding service is not available
* AccountSettings: new option to choose contact group method
* account setup: allow to choose contact group method at account creation
* 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 startup dialogs (F-Droid: donations, Play Store: DRM bug, OpenTasks not installed)
* allow to reset hints/startup dialogs
* AccountSettings: fragment as inner class of activity
Tom Hacohen