Closes #559

Show Responses to Forum Invitations in Private Conversation

Closes #472

See merge request !257

Pause Periodic List Refresh when View is not Visible

This MR also sneaks in a second commit which stops the cevron in the forum list to sometimes lose its blue color. I noticed this when testing this MR with short refresh intervals. This is not as nice of specifying the color as a tint, but unfortunately tints are not yet ready for primetime on Android.

Closes #553

See merge request !259

Closes #553

Show notifications for new blog posts

This also adds a setting allowing people to turn blog post notifications off.

As instructed, this does not yet improve upon the current notification mechanism, but rather follows it, leaving the improvements for  #289.

Closes #488

See merge request !258

This also adds a setting allowing people to turn blog post notifications off.

Closes #488

Closes #472

Show Personal Blog When Clicking On Post in Combined Blog Feed

This is your own personal blog when clicking on your own posts. Note how you can also write posts from that screen and no trust indicator is shown for the posts:
![device-2016-07-28-164921](/uploads/92993d579e26307ee0c6172cfd67bcd8/device-2016-07-28-164921.png)

This is somebody else's blog on a dedicated screen after clicking on a blog post:
![device-2016-07-28-164949](/uploads/d6c18d5b2ea81fd16b0300ae7b76aac5/device-2016-07-28-164949.png)

Closes #415

See merge request !256

Closes #415

Merge branch '535-formatexception-when-loading-contact-list-after-receiving-invitation' into 'master'

Use Client Layer Events in ContactListFragment

This prevents trying to access the same group metadata in different groups.
Also, the conversation does not need to be reloaded once introduction messages arrive.

Closes #535

See merge request !254

Remove PersistentData classes as they aren't thread-safe

This MR depends on !244 and does not claim to resolve *all* issues with the ForumActivity.

Closes #544

See merge request !253

Introduce client layer events for forums

The forum UI depended on sync layer events such as `MessageStateChangedEvent`.
Now, the forum client broadcasts its own high-level event (`ForumPostReceivedEvent`)
with the information the UI needs (`ForumPostHeader`).

Closes #310

See merge request !244

Database queries for metadata only returned it for messages that were delivered already.
However, there are cases (e.g. a pending message needs to be delivered) where
the validator needs to retrieve the metadata from the database.

For these cases, a special database query has been introduced.

The forum UI depended on sync layer events such as MessageStateChangedEvent.
Now, the forum client broadcasts its own high-level event (`ForumPostReceivedEvent`)
with the information the UI needs (`ForumPostHeader`).

Closes #310

Explain why forum can't be shared with contact

Closes #533

See merge request !252

This prevents trying to access the same group metadata in different groups.
Also, the conversation does not need to be reloaded once introduction messages arrive.

Closes #535

Closes #533

Merge branch '515-starting-intent-from-preferences-does-not-work-with-different-app-id' into 'master'

Allow different package IDs (for preference intents)

Closes #515

See merge request !248

Closes #515

Micro Blogs UI

**Attention:** This MR includes several other commits which are supposed to end up in separate MRs. I suggest that you review **per commit**. Once the first two commits have green light, I can split out the other commits into other MRs. This way I don't have to work myself through a long rebase chain every time I make a change to the bottom MR.

This MR is full of commits that introduce features that we will not be using initially. The last commit implements the Micro Blogs UI on top of the framework the first commits establish and hides/disables all future features for now.

I suggest we merge this as is and clean things up later when we have a clearer idea what features we will be doing eventually.

![device-2016-06-23-135016](/uploads/600fc7c28c0c6c4a60d8273ffb55f30a/device-2016-06-23-135016.png)
![device-2016-06-22-181934](/uploads/e57cfbc162150bcd01d4683d4164406e/device-2016-06-22-181934.png)
![device-2016-06-23-142422](/uploads/5814f1e13b6d2230f2e4c12a8c5cd599/device-2016-06-23-142422.png)
![device-2016-06-23-142506](/uploads/d3ac268082b98bbcd068f3d6fe0c6712/device-2016-06-23-142506.png)
![device-2016-06-22-181913](/uploads/f5dcc1ed9a40ec5fa8f634864903f4cc/device-2016-06-22-181913.png)

Closes #436 

See merge request !214

Make it clearer who will be introduced

Show contact names under avatars before sending introduction to make it clearer who will be introduced.

![device-2016-07-08-121836](/uploads/de13f6e75b9a573e561e9c810bbdb08b/device-2016-07-08-121836.png)

Closes #356

See merge request !242

Show all Forum Invitations, not only the first one to prevent cut-offs and forks

This MR solves the problems outlined in #461 by always showing forum invitations, even if the user already subscribed to the forum.

Available Forums have been renamed to Forum Invitations in the UI:

![device-2016-07-07-144141](/uploads/9c8d06decdd19117250e3faca0c38192/device-2016-07-07-144141.png)
![device-2016-07-07-144150](/uploads/9803f567c962a721b24d79359974a29f/device-2016-07-07-144150.png)

Closes #461

See merge request !241

Improved the contact addition header

Closes #459

See merge request !245