* use cert4android instead of MemorizingTrustManager
* new app setting: distrust system certificates
* add network security config to manifest so that user-installed CAs will be accepted in Android 7 again
* update gradle
* allow ProGuard optimization to remove non-relevant bytecode from flavors
* check flavors with direct comparison instead of .equals() to allwo optimizations
* store cookies per HttpClient, and not per DAVdroid instance (allows multiple sessions for parallel syncs)
* fetch translations from Transifex
* 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
This reverts commit 3bde3758fc.
Version bump to 1.0.9.1
Reason: A server MAY reject a request that contains a message body but not a Content-Length
by responding with 411 (Length Required). (RFC 7230 3.3.3 Message Body Length)
* upgrade to okhttp 3.3 to reduce HTTP/2 incompatibilties
* vcard4android: enable RFC 6868 support in ez-vcard
* minor improvements and bug fixes
* new translations from Transifex
* version bump to 1.0.9
* use weak references for DavService RefreshingStatusListener
* additional null checks for cases which shouldn't appear, but apparently appear
* additional database conflict handling for cases which shouldn't appear, but apparently appear
* setup by URL: null check for empty host names
* vcard4android: upgrade to ezvcard 0.9.10
* catch IllegalArgumentException from HttpUrl in DavResourceFinder (caused crash when logging in with email "test@server/withslash")
* use IteratorChain in DavService collection enumeration
* task list synchronization: don't set VISIBLE=1 and SYNC_ENABLED=1 at every sync, but only at creation
* task list synchronization: sync only task lists which are SYNC_ENABLED
* honor "manage calendar colors" account setting for task list colors, too
* add run-tests-connected.sh, to be used as pre-commit hook
* ical4android/vcard4android tests
* fetch translations from Transifex
* version bump to 1.0.7
* don't set ORGANIZER for events without attendees
* make some lists public final instead of @Getter private
* PermissionsActivity: call refresh in onResume() instead of onCreate()
