Require a label for signing

This adds a sign() and a verify() method to the CryptoComponent
that take a mandatory label argument to ensure that signatures can't be
repurposed.

Closes #549

See merge request !419

Add visibility information to group member list

![device-2016-11-17-120740](/uploads/f16dd42c3637e0030722559bace9c391/device-2016-11-17-120740.png)![device-2016-11-17-121008](/uploads/a83fe1f27cd3a505cf45a94fec76cdcf/device-2016-11-17-121008.png)

Closes #754

See merge request !418

use SHOW_IMPLICIT when showing the softkeyboard, otherwise it won't auto hide

* remove the forced hiding in ThreadListActivity as it should no longer be required

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

Closes #761

See merge request !421

Activity module refactor

Broke the Activity module into numerous modules to be able to make numerous controller's package visible

Closes #752

See merge request !417

This adds a sign() and a verify() method to the CryptoComponent
that take a mandatory label argument to ensure that signatures can't be
repurposed.

* remove the forced hiding in ThreadListActivity as it should no longer be required

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

Use namespaced strings for Transport IDs

Closes #558

See merge request !420

Do not track incoming positive introduction responses

Positive introduction responses are not shown in the UI (for introducees) and are therefore not marked as read. If they would be tracked, the unread message count would be higher than it actually is and would never decrease.

This is a minimal fix that could be better, but I didn't bother to refactor anything, because we need to rewrite the introduction client eventually anyway once more.

Closes #759

See merge request !416

because they are not shown in the UI and are therefore not marked as
read. This fixes the unread message count.

Remove unnecessary unmodifiable collection wrappers

Part of #379.

See merge request !414

Unit tests for some validators

See merge request !413

Use new group visibility state to avoid lost messages

Depends on !410. Closes #756.

See merge request !411

Add third group visibility state

This branch adds a third group visibility state: each group is either invisible, visible, or shared with respect to each contact.

Invisible means that the contact doesn't see any sign that we subscribe to the group. Visible means that the contact can send us messages in the group, but we won't send the contact messages in the group. Shared means that the contact can send us messages in the group and we'll send the contact any shared messages in the group.

This is a preparatory step for #756. I'll put up another MR with the changes that close that ticket.

See merge request !410

Use MessageTracker for private group invitation messages

Depends on !405.

See merge request !412

Factor MessageTracker out of BdfIncomingMessageHook

The branch moves the MessageTracker implementation from BdfIncomingMessageHook to a separate class. This will allow the private group invitation client to track messages from classes other than the one that implements the delivery hook.

I've also fixed a couple of bugs, removed some redundant code from the validation manager, and added null-safety annotations (which is how I noticed the bugs).

See merge request !405

Add visibility and OPTIONS button to private group join notices

![device-2016-11-11-180658](/uploads/e00d175a1e1f34307c5f0d80fa0d1cdf/device-2016-11-11-180658.png)
![device-2016-11-11-181325](/uploads/0f6010094d529a4f151db8ebce974885/device-2016-11-11-181325.png)

Closes #732

See merge request !408

Made private group timestamp greater than that of latest message

I did not change `getPreviousMsgId()` to `getPreviousMsgHeader()` because there doesn't seem to be a need for it anymore.

Closes #755

See merge request !409

Add onboarding dialog for revealing contacts screen

This MR is based on !406.

![device-2016-11-11-162417](/uploads/8df831905eebf41ecdbe368890cdd429/device-2016-11-11-162417.png)

See merge request !407

Add UI for revealing contacts within a private group

This addresses one part of #732. Join notices and onboarding will follow in separate MRs.

Although this MR is technically not based on !402, it does require it to be merged first to compile.

![device-2016-11-11-160454](/uploads/8cb6d8bdd0f3761657875024739e730a/device-2016-11-11-160454.png)

See merge request !406

Mark relationship visible when syncing group with peer

This branch updates the private group invitation protocol to use @grote's new method for marking a contact relationship visible to the group.

I've changed the method slightly because the protocol state machine allows us to leave and re-enter the BOTH_JOINED state (see diagram on #659), so the relationship may already be visible when the method is called. In that case the visibility isn't updated, so we stick with whichever of revealed-by-us and revealed-by-contact happened first.

See merge request !402