Remove blog pagers

I set out to fix potential race conditions in the blog pagers (the screens you reach by tapping the body of a blog post, that allow you to swipe left and right through the posts in the combined feed or a single blog). The race conditions here are similar to those addressed by !356, but the adapters don't inherit from BriarAdapter so they need to be fixed separately.

While I was looking into this I found a few minor problems with the pagers:
* The feed pager wasn't responding to events - this was fixed in !398
* The feed pager finishes NavDrawerActivity when any blog is removed
* The feed isn't updated when a blog is added (this applies to the list view as well as the pager)
* Posts aren't removed from the feed pager when a blog is removed

The last problem is quite serious - the feed pager's adapter contains posts that are no longer in the DB, so they'll fail to load. To fix that problem, the adapter needs to be cleared in onStop() and repopulated in onStart(). This is the same approach we use for other adapters where items can be removed from the underlying dataset. Unfortunately, FragmentStatePagerAdapter has some odd behaviour when you clear and repopulate it:

1. When reselecting the previously selected item after clearing and repopulating the adapter, the item slides into view instead of just appearing, which makes it look like you've accidentally swiped.
2. Items are sometimes duplicated when clearing and repopulating the adapter, so swiping left or right shows another copy of the same post.

These problems only seem to happen if the adapter is cleared - adding new posts works fine on master, although I think there might be some luck involved - FragmentStatePagerAdapter doesn't seem to be designed to support items changing positions.

I spent a lot of time trying to resolve these problems before concluding that maybe it wasn't worth it, and we should just remove the pagers. That's what's currently implemented in this branch. Tapping the body of a post will show the full-length post, but you won't be able to swipe left or right.

The swiping functionality was nice to have, so if you have ideas for fixing the bugs I'd love to hear them. But I'd rather remove this functionality than keep it in a buggy state with no plan for how to fix it.

Closes #705

See merge request !400

Add integration tests for GroupInvitationManager

This MR is based on !433. It adds some integration tests for the private group invitation protocol. One of those tests fails at the moment.

It does not yet cover all corner cases, so it does not fully address #760, but addresses a part of it. Suggestions for more scenarios to test are welcome.

[Wording changed to prevent #760 from being closed automatically based on the description.]

See merge request !434

Refactor Integration Tests

This is quite a massive MR (currently 1763 additions and 3482 deletions). However, there's not so much happening. The only thing I did was moving redundant code from the various protocol integration tests to the `BriarIntegrationTest` class.

All integration tests are still passing.

Closes #727

See merge request !433

Add unit tests for group validators

Part of #766

See merge request !436

Add unit tests for group invitation client

Part of #766

See merge request !429

Fix Contacts Item always beeing selected if Back is pressed in the NavMenu

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

Closes #782

See merge request !438

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

Select the correct MenuItem when Back is pressed in NawDrawer

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

Closes #782

See merge request !437

Bring back the toolbar shadow

![device-2016-11-21-180111](/uploads/7cd5e6a1e7a4b79b6d7cf81377b148a0/device-2016-11-21-180111.png)

Closes #477

See merge request !431

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

Make navigation drawer scrollable

![device-2016-11-22-095642](/uploads/bcd5f68d40816ed2e44c3194eb977695/device-2016-11-22-095642.png)![device-2016-11-22-095658](/uploads/da1807e981632936ba04db24dc7b8ae7/device-2016-11-22-095658.png)

Closes #666

See merge request !432

Make dialog actions consistent

Closes #504

See merge request !430

Use uuid created from the commitment/payload instead of the uuid returned from getUuid()

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

Closes #774

See merge request !435

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

Remove injected field from unit test

Getting this off my todo list...

Closes #747

See merge request !428

Make original author look like commenter when reblogged

This wasn't as simple as changing the persona in the XML,
because the same layout is used for a post whether reblogged or not.
So the persona needs to be changed programmatically for reblogged posts.
For this, the `AuthorView#setPersona()` method has been made public and
was changed to always set all views into the desired state to support
usage in a RecyclerView.

![device-2016-11-21-094221](/uploads/e508937ad2d2d84f97f5be29bdeaac2e/device-2016-11-21-094221.png)

Closes #639

See merge request !426

Fix KeyAgreement after regression

Closes #768

See merge request !427

This wasn't as simple as changing the persona in the XML,
because the same layout is used for a post whether reblogged or not.
So the persona needs to be changed programmatically for reblogged posts.
For this, the `AuthorView#setPersona()` method has been made public and
was changed to always set all views into the desired state to support
usage in a RecyclerView.