* 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)
* 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
* honour calendar-proxy-read/write-for property
* ignore errors when quering member groups for home sets
* remove home sets and collections from the service database not only on 404, but 403, 404 and 410
* fix crash bug when <displayname> was defined, but empty
* 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
* 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
* ical4android: enumerate (=synchronize) all task lists and not only the first one
* fix crash bugs when activating external logging without external storage
* fix lint warnings
* line-break too long messages of network trace logs
* DebugInfoActivity "send": attach log file instead if sending it as plain text
* revert to ez-vcard 0.9.6 because of https://github.com/mangstadt/ez-vcard/issues/33
* German translations
* new StringLogger
* DavResourceFinder: log to StringLogger; if no collections are found, logs can be views
* DebugInfoActivity: show passed logs
* script to fetch translations from Transifex
* increase version to 0.9-beta2
* 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
* check whether user-given URL actually provides CalDAV/CardDAV before trusting the current-user-principal
as there may be different principals for CalDAV and CardDAV (if both services are completely separated)
* 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)
* resource detection is subject to change yet
* don't use UID_2445 for Android <= 4.1
* more useful sync error notification messages
* handle 401 Unauthorized and show account info when notification is tapped
* use VERSION_CODE and buildTime from BuildConfig
* new HTTP User-Agent, VCard PRODID values
* contact sync: store CTag in SyncState
* sync logic: upload contacts, check CTag, multiget
