* 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
* 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
* 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
* increase target API level to 23 (Android 6), which makes Android 6-style permissions mandatory
* AUTHENTICATE_ACCOUNTS permission is only required up to API level 22
* new activity: PermissionsActivity which shows missing permissions and provides buttons to request them
* DavService: Android shouldn't send a null Intent, but sometimes it does, so implement null check
* LocalTaskList: tasksProviderAvailable may return true on API level 23+ even if permissions are not sufficient
* SyncAdapterService: show a notification (with Intent for PermissionsActivity) when permissions are not sufficient
* when creating accounts, set OpenTasks sync always to true if API level is 23+ (even if OpenTasks is not installed [yet])
* update Lombok
* 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 ACCOUNT_NAME and ACCOUNT_TYPE when creating calendars
* close TaskProvider when checking for its presence
* when TaskProvider is not available/accessible, explicitly disallow task sync at account creation
to prevent further crashes
* try to handle OutOfMemoryError
* version 1.0_2
* re-initialize logger in :sync process after changing the settings (IPC using broadcast)
* move settings from SharedPreferences (which is not multi-process-safe) to ServiceDB
* logger: show exception details
* settings: show debug info
* 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
* 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
