* CryptoNextBeta: (60 commits)
  Lock TrustKeys if no trusted keys are available
  Optimize imports
  Use MD style for key trust toggle switch
  Fix set/remove OnUpdateBlocklistListener
  Fix axolotl database migration
  Remove device list from EditAccount
  Add clear devices to overflow menu in EditAccount
  Ask for key trust when sending messages
  Encrypt files for HTTP upload in encrypted chats
  Refactor trust key ui and show in account details
  Send correct body for HTTP files
  Handle file transmission properly in axolotl
  Remove unneccessary code
  Fix trust status for outgoing messages
  Don't merge messages with different trust statuses
  Fix copying of axolotl keys to clipboard
  Add refresh icon to v21 theme
  Disable Axolotl option if not usable
  Show trust status of messages' originating session
  Add key trust toggle to ContactDetailsActivity
  ...

show contact details in conference details ...

Can't call getWritableDatabase in recreateAxolotlDb()

Change CAB to accent color in v21

If the contact (or the own account) has keys that have UNDECIDED trust,
we now drop the user into the new TrustKeysActivity, where they have to
decide for each new key whether it should be TRUSTED or UNTRUSTED.

Refactored the trust key row UI element so it can be used in multiple
places. It now also uses a slider to toggle the trust state, and the
redundant trust state description was removed.

EditAccountActivity now shows the keys of other devices associated with
that account.

When using HTTP upload to send files, take care to transmit only the URL
rather than the entire body, which contains metadata.

Tag sent messages with own fingerprint, set own fingerprint as always
trusted, include own fingerprint in database trust search, explicitly
reset trust colorfilter

In MUCs or if contact is not axolotl capable, disable axolotl menu
option

Shade lock icon red if message was received in a session that has not
been marked trusted by the user or fingerprint is unknown

Can now toggle IdentityKey trust

Any time a new session is established, call syncRosterToDisk() to ensure
that on subsequent restoreFromDatabase() calls, the roster is actually
available. This is important so that initAccountServices() can properly
initialize the SessionMap. This prevents a race condition where after
adding a new account and initiating sessions with it, if the app is
killed (e.g. by reinstall) before triggering a syncRosterToDisk(),
subsequent restores will not have the roster available, leading to
missing XmppAxolotlSessions in the SessionMap cache. As a result of
this, a new session was initiated when sending a new message, and
received messages could not be tagged with the originating session's
fingerprint.

As an added sanity check, go to the database to confirm no records are
present before creating fresh XmppAxolotlSession objects (both in the
sending and receiving case).

Added proper UNIQUE statement

Wipe session cache to prevent stale sessions being used. Wipe fetch
status cache to enable recreation of sessions. Regenerate deviceId, so
that foreign devices will talk to us again.

Messages are now tagged with the IdentityKey fingerprint of the
originating session. IdentityKeys have one of three trust states:
undecided (default), trusted, and untrusted/not yet trusted.

The AxolotlService depends on the roster being loaded when it is
initialized so that it can fill its in-memory SessionMap.

Add a fixed prefix to axolotl-related log messages, set log levels
sensibly.

EditAccountActivity now show own fingerprint, and gives an option to
regenerate local keying material (and wipe all sessions associated with
the old keys in the process).

It also now displays a list of other own devices, and gives an option to
remove all but the current device.

No longer store own device ID (so that we don't encrypt messages for
ourselves), verify that own device ID is present in update list
(otherwise republish), reflect update in UI.