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

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

Source: https://github.com/saiimons/Android-Identicons
License: Apache License, Version 2.0

Removed consumers from BdfWriter. #234

Cleaning up some unused code.

See merge request !76

Navigation drawer (squashed and rebased).

This is @ernir's work on #30 and #181, rebased onto master with recent changes to ConversationActivity and ForumListActivity ported to the respective fragments.

See merge request !75

Show Bluetooth address from Settings.Secure in TestingActivity

* To help with investigating #225 (and maybe other bugs in future), show the Bluetooth address from Settings.Secure as well as the address from BluetoothAdapter.getAddress()
* Add Settings.Secure.ANDROID_ID to the entropy pool - it may provide up to 64 bits of extra entropy from the perspective of a remote attacker (no extra bits from the perspective of a local attacker in the same user account, who sees the same ANDROID_ID)


See merge request !73

Replaced broken jsocks jar. #228

Fixes #228 and may also fix #217. @str4d and @grote, please test and confirm.

See merge request !72

Update contact list when contacts are deleted. #227

The logic in ConversationActivity for adding or updating items didn't allow for items being removed. We *could* come up with logic for doing that - throw all the items from the adapter into a set, remove any items corresponding to current contacts from the set, then batch update the adapter to remove any items remaining in the set - but I think it would be overly complex. It's simpler to just clear the adapter and add the current contacts.

Also tidied up some adapter code while looking for the bug.


See merge request !70

Don't disable Bluetooth unless we enabled it. #226

Fixes #226

See merge request !71

Metadata for groups. #221



See merge request !69

Also removed unnecessary adapter notifications in various places.

Run hooks when contacts/identities are added/removed. #209

Now that the sync layer is separated from its clients, actions that used to occur within the DatabaseComponent, such as adding or removing private groups when adding or removing a contact, have to be handled by clients.

This patch adds a mechanism for clients to register hooks with the Contact/IdentityManager to be run when contacts/identities are being added/removed. The MessagingManager uses ContactManager hooks for adding and removing private groups, and the ContactManager uses IdentityManager hooks for removing contacts when an identity is removed.

I've also changed the way some components register with the LifecycleManager and EventBus.

This merge request depends on !64 - I'll merge them at the same time. Closes #209.

See merge request !68

Whether or not a class needs to run as a service is an implementation decision.

Separate the sync layer from its clients. #112

This patch contains most of the work for #112. MessagingManager and ForumManager have been converted to BSP clients, and the sync layer's message and group formats no longer contain any client-specific data.

Each client has a MessageValidator that's called by the ValidationManager to validate messages belonging to the client. A new MessageValidatedEvent informs listeners when a message has been validated. This required some changes to the UI, especially the notification manager.

While working on the notification manager I realised it was calling Android API methods from background threads, which may be unsafe, and the notification logic was split across BriarService and AndroidNotificationManagerImpl. So I refactored those classes, along with AndroidExecutorImpl, which was using an unnecessary background thread.

Still to do:
* Synchronise blocks, not messages
* Add message type field to message header as per BSP spec
* Convert TransportPropertyManager into a BSP client
* Convert SubscriptionUpdates/Acks into forum client messages


See merge request !64

ENH: Replaces transport config with namespaced settings

This MR contains the following:

* Adds a new guice module: SettingsManager, that abstracts the settings interface from the underlying database
* Uses SettingsManager to replace the db.getConfig/mergeConfig calls in the Settings activity
* Replaces the getSettings and mergeSettings calls in the database modules to include a namespace parameter. Updates the corresponding queries in the Jdbc module
* Removes the TransportConfig module, as it is not used anymore
* Updates the DuplexPlugin interface, to reflect this change in schemas and calls
* Updates the calls in the corresponding plugins, for both briar-android and briar-desktop
* Updates the hardcoded plugins in the tests to reflect these changes and updates the unit tests.

See merge request !65

Fix adding contacts with Android 6

Adds `ACCESS_COARSE_LOCATION` permission to manifest. Since API 23 this is required for access to the Bluetooth APIs.

See: https://developer.android.com/intl/ko/about/versions/marshmallow/android-6.0-changes.html#behavior-hardware-id

Closes #223

See merge request !67