Merge tag 'v2.3'

Conflicts:
	AndroidManifest.xml
	src/com/ichi2/anki/AbstractFlashcardViewer.java
	src/com/ichi2/anki/BackupManager.java
	src/com/ichi2/anki/BroadcastMessages.java
	src/com/ichi2/anki/CardBrowser.java
	src/com/ichi2/anki/DeckPicker.java
	src/com/ichi2/anki/NoteEditor.java
	src/com/ichi2/anki/Previewer.java
	src/com/ichi2/anki/StudyOptionsFragment.java
	src/com/ichi2/anki/multimediacard/fields/BasicImageFieldController.java
	src/com/ichi2/async/Connection.java
	src/com/ichi2/async/DeckTask.java
	src/com/ichi2/charts/ChartBuilder.java
	src/com/ichi2/libanki/Collection.java
	src/com/ichi2/libanki/Sched.java
	src/com/ichi2/libanki/sync/MediaSyncer.java
	src/com/ichi2/libanki/sync/Syncer.java