1) Fix bugs that prevented decrypt() from being non-transactional
in some cases.
2) Introduce a new unified storage interface.
3) Transition simultaneous initiate from the "needs refresh"
strategy to one that uses session state resurrection and
promotion.
1) Since we're not CPU or space constrained (and are in fact
padding), and since keystream reuse would be more catastrophic
than IV reuse without chosen plaintext.
1) ephemeralKey -> ratchetKey
2) Have the caller specify Alice/Bob orientation.
3) Reorganize verification tag.
4) Remove verification tag from key exchange messages, replace
with signatures in both directions.
1) Change SessionBuilder to only establish sessions via
KeyExchangeMessage and PreKeyBundles.
2) Change SessionCipher to decrypt either WhisperMessage
or PreKeyWhisperMessage items, automatically building
a session for the latter.
3) Change SessionCipher to tear down new sessions built
with PreKeyWhisperMessages if the embedded WhsiperMessage
fails to decrypt.
1) Use the new /v2/keys API for storing/retrieving prekey bundles.
2) For sessions built with PreKeyBundle and PreKeyWhisperMessage,
use a v3 ratcheting session when available.
1) Add plain two-way key exchange support libaxolotl by moving
all the KeyExchangeMessage code there.
2) Move the bulk of KeyExchangeProcessor code to libaxolotl
for setting up sessions based on retrieved prekeys, received
prekeybundles, or exchanged key exchange messages.
1) Break the core cryptography functions out into libaxolotol.
2) The objective for this code is a Java library that isn't
dependent on any Android functions. However, while the
code has been separated from any Android functionality,
it is still an 'android library project' because of the
JNI.
