New Forum Sharing Client

This is very similar to how the private group invitations work and I am sure there's still some tiny bugs that I didn't catch.

All existing integration tests either pass or have been modified to pass.

Once this has been merged, the code should be usable for blog sharing as well.

Closes #475

See merge request !467

Fix ForumActivityTest and get rid of redundant theme definition

Closes #881

See merge request !474

Fix memory leaks caused by periodic view refreshing tasks

This branch implements @goapunk's suggested solution to #851. Credit goes to @ernir for finding the bug and the initial solution, and @goapunk for the improved solution - I just did a quick implementation so we can get this fixed as quickly as possible.

Closes #851

See merge request !473

Merge branch '710-conversationactivity-uses-uninitialised-field-as-format-string-argument' into 'master'

Make sure contact name is initialized when needed

This uses a Listenable Future and unfortunately requires 4 basically identical methods to handle the incoming events. Any suggestions for improving that are welcome.

Closes #710

See merge request !472

Do not log information from RSS feeds

Closes #882

See merge request !475

Unit tests for record readers

I thought we should have some tests for the new logic that skips unrecognised record types.

See merge request !471

Use unique request codes across the app

Closes #742

See merge request !470

Add a handleDbException() method to BaseActivity

This adds a `handleDbException()` method to BaseActivity and a corresponding method for fragments that calls through to the activity.
For now, the method just finishes the activity
and NavDrawerActivity overrides it to do nothing,
and all the error places marked with TODO that finish the activity call the method instead.

That gives us zero functional improvement over the status quo,
but it allows us to change the default behaviour easily,
and then we can start thinking about which cases should have non-default behaviour.

First part of #469

See merge request !469

Mark invitation unavailable to answer when creator dissolved the group after the invitation.

Closes #876

See merge request !468

and a corresponding method for fragments that calls through to the activity.
For now, the method just finishes the activity
and NavDrawerActivity overrides it to do nothing,
and all the error places marked with TODO that finish the activity call the method instead.

That gives us zero functional improvement over the status quo,
but it allows us to change the default behaviour easily,
and then we can start thinking about which cases should have non-default behaviour.

after the invitation.

Closes #876

Bring protocols in line with spec

Closes #628

See merge request !465

Show open button in private conversation after accepting invitations

To keep the implementation simple, the Open button does appear where the Accept button had been previously.

In order to make the Open button functional, I had to make the `GroupId` of the invitation target available to the UI. Most code in this MR is due to that.

![device-2016-12-13-105228](/uploads/d0f27fc02f1411596458d9203a0810d2/device-2016-12-13-105228.png)

Closes #793

See merge request !457

Ignore QR code results until local QR code is created

* Make scanning only possible after we are "ready" (= our QrCode was created and set).

Signed-off-by: goapunk <noobie@goapunks.net>

Closes #814

See merge request !454

Also show overflow icon on devices with menu key by using Toolbar

Closes #738

See merge request !463

Update all logos

The launcher icons are now in mipmap folders which is the recommended practice, because on a low-res device, the high res drawables are stripped from the app. This is bad when the user decides to show the app icons really big on the launcher and the high-res drawables are not available anymore.

The old launcher icon seemed to have some sort of 3D effect.
![device-2016-12-13-134037](/uploads/84db532df3821ad74ba57719f0763b7b/device-2016-12-13-134037.png)

Navigation Drawer Old:
![device-2016-12-13-124112](/uploads/465b817d2e0bbbd50b461ea32686c933/device-2016-12-13-124112.png)
Navigation Drawer New:
![device-2016-12-13-132428](/uploads/3c3530bfc515525dd8f66abfa52d1142/device-2016-12-13-132428.png)

Closes #828

See merge request !459

Use different notification icons for different features

![device-2016-12-13-151008](/uploads/2c9aa33c230738b5ea20a76ac5e3b214/device-2016-12-13-151008.png)
![device-2016-12-13-150954](/uploads/85acd46fc6afd3aebcc1fcd015b041d7/device-2016-12-13-150954.png)

Closes #795

See merge request !460

Include Commit ID in crash reports and feedback

Closes #697

See merge request !461

and use the primary color for the notification.

Plugins throw exceptions for startup errors

Please review carefully as I don't know much about the code I have touched here.

Closes #285

See merge request !462