Release camera surface to work around Android bug #54285

Closes #680

See merge request !340

Clean up identicon code, remove unused classes

I noticed some debug-level logging coming from the identicon code, went in there to remove it, and realised half the code was unused, so I removed that too.

No functional changes except that the logging is gone and the opacity is now OPAQUE rather than UNKNOWN, which wasn't valid in this context.

See merge request !339

Remove loading callbacks from fragment listener

Now fragments are responsible for their own Progress bars.

Closes #642

See merge request !316

Emoji Support for all user input

All text that can be generated by users will show emoji from the shipped sprites by using the `EmojiTextView` instead of the normal `TextView`.

For all messages and posts, the custom emoji keyboard is now available as well. For this, a new `LargeTextInputView` has been introduced that is a sub-class of `TextInputView`. In order for the emoticon keyboard to work properly the existing views had to be modified heavily, sometimes resulting in new behavior such as scroll views now being above the fixed input field. Actual testing on a device (preferably with a tiny screen) is recommended to make sure this still works as expected. Screenshots will be included at the end of this post.

This MR also disables menu actions rather than hiding them and it includes a fix for a regression that was not showing the keyboard automatically in forums.

![device-2016-09-28-104914](/uploads/8ce9c8f61b32dc5a46b89a3a2cf1e6a4/device-2016-09-28-104914.png)
![device-2016-09-28-105026](/uploads/96ef9c40547c7a44fbc4517c87637a7e/device-2016-09-28-105026.png)
![device-2016-09-28-105041](/uploads/a0d1ed23ccb66e8bf9541737407142e3/device-2016-09-28-105041.png)
![device-2016-09-28-105440](/uploads/fb76ed2adc87600cfb0fc33c3962d4a6/device-2016-09-28-105440.png)
![device-2016-09-28-105515](/uploads/51f845d697cee3df38d1b9eef3c0ddfc/device-2016-09-28-105515.png)

Closes #92

See merge request !329

Fix regression in IntroduceeManager

This was happening when the remote response arrives before the local
response is made and thus the local response needs to be send with the
ACK following. The problem was that we ACK was sent before the response
which is not allowed and resulted in the session being aborted by the
introducee. This was happening, because recursion is hard ;)

The fix is only restarting another protocol engine to send the ACK
after the first run has been completed.

An integration test was added to prevent such regression in the future
and to test this code path.

Closes #695

See merge request !338

This was happening when the remote response arrives before the local
response is made and thus the local response needs to be send with the
ACK following. The problem was that we ACK was sent before the response
which is not allowed and resulted in the session being aborted by the
introducee. This was happening, because recursion is hard ;)

The fix is only restarting another protocol engine to send the ACK
after the first run has been completed.

An integration test was added to prevent such regression in the future
and to test this code path.

Don't show introduction onboarding again no matter how dismissed

Closes #690

See merge request !337

All text that can be generated by users will show emoji from the
shipped sprites.

For all messages and posts, the custom emoji keyboard is now available.

This also disables menu actions rather than hiding them and thus
closes #677

Included is a fix for a regression that was not showing the keyboard
automatically in forums and thus
closes #676

Create PrivateGroupManager Facade and stub implementation

Some classes were renamed and new base classes introduced in the process. I suggest to expand the "Changed files" before reviewing to get an overview over the changes.

Closes #673

See merge request !332

Fix integration tests

First problem was a race condition with message delivery and the second
one due to the fact that we no longer plan to allow adding of additional
blogs, so the test for that has simply been removed.

See merge request !333

Check length of text after spanning

Closes #685

See merge request !334

First problem was a race condition with message delivery and the second
one due to the fact that we no longer plan to allow adding of additional
blogs, so the test for that has simply been removed.

The app _name string is marked as non-translatable and the new_identity_item string no longer exists.

Forum controller thread safety and tree safety

This branch solves the concurrent forum issues by code restructure and refactoring.

Closes #556 
Closes #552 

See merge request !262

Remove toolbar animation to fix the missing toolbar on first start

Closes #644

See merge request !331

Prevent personal blogs from being removed

This also adds unit tests to prevent regressions like this in the future.

Closes #679

See merge request !330

When a message is shared, share its transitive dependencies

Like other recursive operations on the dependency graph, this is
not done in a single transaction to prevent an attacker from creating
arbitrary large transactions.

So at startup, the `ValidationManager` finds and resumes any
unfinished operations, by looking for unshared messages with shared
dependents.

Closes #589

See merge request !325

Like other recursive operations on the dependency graph, this is
not done in a single transaction to prevent an attacker from creating
arbitrary large transactions.

So at startup, the `ValidationManager` finds and resumes any
unfinished operations, by looking for shared messages with unshared
dependencies.

This also adds unit tests to prevent regressions like this in the
future.

Try harder to find suitable camera parameters

This branch fixes QR code scanning on the Galaxy Nexus running Cyanogen Mod 12.1 (Android 5.1.1), without breaking QR code scanning on any of the other test devices.

The problem on the Galaxy Nexus was that the selected scene mode was overriding the selected focus mode, so we asked for continuous picture mode but got macro mode. Macro mode requires startAutoFocus() to be called, but we weren't calling it because we'd asked for continuous picture mode.

The fix for that problem is to query the focus mode after applying the parameters and call startAutoFocus() based on the actual mode rather than the requested mode.

But then I discovered another problem: barcode scene mode was setting the flash to auto, so in low light the flash was turning on and off while trying to scan QR codes. That might work well for printed QR codes, but it's terrible when scanning from a screen.

The fix for the new problem is to select barcode scene mode, then try to disable the flash, and if that fails, reset the scene mode. Then we pick the best available video stabilisation, focus mode and preview size.

On the Galaxy Nexus with CM 12.1, that means we use continuous picture mode instead of barcode scene mode, which works fine. All the other test devices pick the same settings as before.

See merge request !321

Check whether File#listFiles() returns null

The docs say this can happen if there's an I/O error. Also fixed a throw-in-finally-block warning and renamed an IoUtils method to make its contract clearer.

See merge request !328

The docs say this can happen for a directory if there's an I/O error.

Remove base32 TODOs, fix a potential NPE

I thought we'd be able to get higher data density in QR codes by using base32 instead of base64, allowing the QR code to use alphanumeric mode instead of byte mode. But I tried it, and although the QR code does use alphanumeric mode, it comes out at exactly the same size (see the 346-use-base32-for-qr-codes branch). So this MR removes the TODOs and fixes a potential NPE I spotted while working on the other branch.

See merge request !327

Recreate cache directory after deleting app data

This fixes a warning on the Moto G:
```
E/libEGL: error creating cache file /data/data/org.briarproject/cache/com.android.opengl.shaders_cache: No such file or directory (2)
```

@grote might possibly be related to hardware rendering issues.

See merge request !326