* 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
* move AccountSettings up to package context
* HttpClient: take authentication from AccountSettings in the constructor
* App: provide global instance of MemorizingTrustManager
* App: provide global Java logger, optionally with verbose and external file logging
* LoginCredentials: moved from inner-class into setup package
* CalDAV/CardDAV resource list views now always contain all elements without scrolling (NonScrollingListView)
* synchronization action in activity now overriddes system sync settings
* HttpClient: authentication that is limited to a host name is never preemptive
* DavResourceFinder: service configuration == null means that this service is not available
* new SQLite database for CalDAV/CardDAV services
* added AccountDetailsFragment, which asks for account name and then finishes account creation
* updated AccountListFragment
* resource detection: ignore 404 errors when trying context paths
* work around crash when edit field is changed while there is no acitivity (???!)
* dav4android: fix calendar-multiget request
* 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
* ContactsSyncManager: gracefully handle photo URLs without host name
* MainActivity: cache installer package name
* dav4android: use java.util.ServiceLoader to load DAV property factories
* write report to temporary file in external cache dir before sending
* don't delete the report file onActivityResult (because services like the email service may access it asynchronously)
* don't show label of installer (just the package name), because some use ambiguous strings like "App Store" etc.
* show sync. settings for all accounts again
