Store transport properties received by other means

We may receive transport properties while adding a contact, before the first sync connection is made. Store them in the group shared with the contact, flagged as remote properties in the metadata, but don't share them with the contact. Use a version number of zero so any properties synced from the contact will supersede them.

See merge request !92

Allow different identities to have the same contact. #224

Previous fix was incomplete, the DB still had a unique constraint on the author ID column of the contacts table.

See merge request !91

239 proguard dependency cleanup

Closes #239 

See merge request !89

Avoid potential deadlock in TransportKeyManager. #235

See rambling description on the ticket and in the architecture channel...

Fixes #235.

See merge request !79

BQP crypto

This implements the `CryptoComponent` methods necessary for BQP.

Part of #117.

See merge request !88

Remove Ant build files and Eclipse project files.

No longer needed for building or testing, and a pain to maintain.

See merge request !87

Unshared messages



See merge request !86

Factored out code for creating private groups.



See merge request !85

Allow multiple identities to have the same contact. #224



See merge request !82

Don't use external storage for crash/test reports.

Crash/test reports were written to external storage so they could be attached to emails - by putting the information in the body of the email we can avoid needing the WRITE_EXTERNAL_STORAGE permission.

Also updated the email address for crash/test reports.

See merge request !83

Remove unescaped Unicode from tests. #218

Fixes #218.

See merge request !81

Transport properties client. #229

This branch moves support for exchanging transport properties from the sync layer to the client layer.

Local properties are stored in an unshared group. When a contact is added, the latest local properties are copied into a group shared with the contact. Whenever the local properties are updated, they're copied into the groups shared with all contacts.

The transport update messages include a unique device ID that prevents collisions between local and remote messages, and will be used in future for multi-device support.

See merge request !80

Identicons

Closes #120. Part of #82.

I pulled in the identicon code because there is no published library, and also because when I used it for Bote I ended up modifying the code somewhat for my purposes; I expect the same to happen here.

I am not sure what information should be used to seed the identicon. I originally thought of using the public key, but that seemed to change the identicon every single page load (obviously the representation wasn't consistent). Then I tried using the `ContactId`, which was fine until I got to adding an identicon to `AuthorView`: activities that use it are only passed (via Intent) a name, not anything else. Hence `AuthorView` identicons are currently inconsistent with the contact list and conversations.

See merge request !51

I don't care but Android Studio complains.

This was meant to prevent key reuse with BTPv1, it's no longer needed with BTPv2.

This commit renames identicons to avatars in field names, and uses an ImageView
derivative to show the identicons, which should make implementing #214 easier.