1) Switch to new TextSecureAddress addressing, rather than mixing
long-based recipient IDs into libtextsecure.
2) Get rid of RecipientFormattingException throws in calls to
RecipientFactory.
Closes#2570
1) Migrate from GSON to Jackson everywhere.
2) Add support for storing identity key conflicts on message rows.
3) Add limited support for surfacing identity key conflicts in UI.