* ui: types and stubs to encrypt local files
* ios: encrypt automatically received images in local storage
* encrypt sent images, marked to be received via NSE
* ios: encrypt sent and received local voice files
* encrypt sent and received local files
* fix NSE
* remove comment
* decrypt files in background thread
* core: add chat items to indicate decryption failures due to ratchets being out of sync
* show ratchet errors in chat items, show all integrity errors
* show decryption errors, tests
* ios: chat items, remove item for duplicate messages
* android: decryption errors chat items
* eol