* Explain what "account creation" means on first run
* Use hints instead of dedicated text views
* Move password strength meter up into the user's view
* Always move user's view to current input field
* Improve "Forgot Password" dialog
Closes#151
Simple Empty State Messages
This MR implements very basic and simple empty state messages for the
current features.
This is how it looks (note that the contact add FAB will be removed soon):




Closes#327
See merge request !236
Font Colors and Separate Themes
Once applied this commit will change the font colors according to the
design and move all themes into a dedicated file.
Closes#333
See merge request !228
Make use of Existing Translations
Adds first translations to source code and sets up transifex config
file. Pull more translations later with:
```bash
cd briar-android
tx pull --mode=developer
```
Closes#448

See merge request !226
Adds first translations to source code and sets up transifex config
file. Pull more translations later with:
cd briar-android
tx pull --mode=developer
Closes#448
Fixing fragment instance restore
Alas, it turns out that my neat way of integrating the Fragments into the dependency graph was not without problems. Me and @grote discovered that this presented us with a lot of problems on orientation changes as the Activity is re-created, and therefore parts of the dependency graph. The simplest solution was simply to abandon the idea, i.e. with this branch Fragments are no longer part of the dependency graph.
See merge request !215
Adds badges to the forum list that indicate unread posts
This MR adds badges to the forum list that indicate unread posts. It does so by extending the compound view `TextAvatarView` and provides convenient setters that take care of the required UI changes. The new badge can also be used to indicate a problem with the forum.

I decided not to check if the forum is shared from someone or with someone and indicate a problem in this case, because this requires iterating two times over all contacts and their group metadata for each forum. If someone considers it important to check for this information, we can create a ticket for doing this within the forum and not in the forum list.
See merge request !207
This replaces the custom layouts in the navigation drawer with a
`NavigationView` and adds a menu entry for Blogs.
A Main Blogs fragment is added that holds a `TabLayout` and a
`ViewPager`. Five tabs are already added, but they just have a single
placeholder fragment that is to be replaced by the actual fragments.
Closes#409
It does so by extending the compound view `TextAvatarView` and provides
convienient setters that take care of the required UI changes.
The new badge can also be used to indicate a problem with the forum.
Closes#408
This adds a new table to the database to hold message dependencies.
It introduces two more message states: pending and delivered
The valid column in the database was renamed to state to better reflect
its new extended meaning.
The DatabaseComponent was extended with three methods for:
* adding dependencies
* getting dependencies of a message
* getting messages that depend on a message (dependents)
* getting messages to be delivered (by startup hook)
* getting pending messages to be possibly delivered (by startup hook)
In order to reflect the new states, things that were previously true for
VALID messages have been changed to now be true for DELIVERED messages.
Since pending messages should not be available to clients, many database
queries have been modified to only return results for delivered
messages.
All added methods and changes should come with updated unit tests.
Please note that the database version was bumped in this commit.
The new activity shows who you are sharing a forum with and who shares a
forum with you. It is accessible from the overflow menu when in a forum.
Closes#398
Contact List Unread Messages
Adds unread count as bubble to avatar image in contact list.
Please note that this is based on !190.

Closes#399
See merge request !192
Increase Avatar border and change shadow color


See merge request !190
The code for creating forums in ForumManager was used by
ForumSharingManager and also needed by InviteeEngine.
This extracts it into its own class.
Closes#375