Add BQP support to LanTcpPlugin

Closes #385

See merge request !185

Add forum avatars to list of available forums

![device-2016-05-11-152154](/uploads/864b4f42f35afe4a1dadc6cd42fa730d/device-2016-05-11-152154.png)

Closes #374

See merge request !182

Closes #374

Forum Avatars

These new forum avatars are using the first letter of the forum and calculate the background color from forum's group ID.

Closes #337

![device-2016-05-11-124106](/uploads/afe926066f4306500c6ee23bb93b5b5b/device-2016-05-11-124106.png)

See merge request !178

Also prevents the snackbar from hiding the bottom of the list.

Closes #337

Start plugins asynchronously

This prevents other services from getting stuck behind the plugin manager while the Tor plugin is starting, which takes several seconds. The plugin manager waits for each plugin to start before stopping it.

I've also added some canaries to plugins and services to ensure instances aren't started more than once.

See merge request !181

Poller refactoring, replace Timer with ScheduledExecutorService

* Replace Timer with ScheduledExecutorService (closes #258)
* Move automatic connection logic from PluginManager to Poller
* Reschedule polling when connections are opened or closed, making the poller more responsive to reductions in the polling interval


See merge request !180

Collect dev report data on a thread with a looper

Closes #328.

See merge request !166

274 code encapsulation

The goal of this branch is to better compartmentalize, structure and simplify the code in the Android module. It does this via the following techniques:

* Extended use of Dagger by introducing a component for Activities that injects, among other things, SharedPreferences and Fragments. The latter makes it possible to mock fragments more easily and letting Dagger automatically handle its injections.
* Decouple Briar API code, from the activities and Fragments, and encapsulate in re-usable Controller classes
* Introduce a UI-thread App event bus that the Helper classes use to communicate with Activities & Fragments.
* Define the testing methods in the briar-android module per Robolectric and Mockito

NOTE! Don't be alarmed if you see the contact introduction message one more time, one of the changes was to purify UI shared preferences from the Briar shared preferences, which now only contain preferences related to the API and it's usage.

closes #274 



See merge request !130

Switched AppBus for ResultHandler, Controller for Helper. Added the basics for LifecycleControllers and implemented it for BriarActivity and NavDrawerActivity

Forum Sharing Client UI

This changes `ShareForumActivity` to use two fragments to facilitate
forum sharing with the new Forum Sharing Client backend.

The `ContactSelectorFragment` allows the user to select a
number of contacts. If there is an ongoing sharing session or the forum
is already shared with the contact, it is disabled in the list. If there
is at least one contact selected, a button appears in the toolbar that
brings the user to the `ShareForumMessageFragment` where the user can
write an optional message to be send along with the invitation.

After sending an invitation, the user is brought back to the forum that
she shared and there is a snackbar showing up briefly to indicate the
successful invitation.

The invitation is shown along with the message within the private
conversation of each contact. The person who shares the forum also sees
the invitation and the message as outgoing messages that also display
the current status of the messages.

A notification is shown like for other private messages as well.

Please note that this commit does not include a way for users to respond
to invitations. This is in MR !172. Both MRs are based on the new backend in !170.

![device-2016-05-03-182928](/uploads/48499ca4c149a8e7f13f8b28a24537ad/device-2016-05-03-182928.png)
![device-2016-05-03-182855](/uploads/5f49c43bf8f39780862247848a5b9c27/device-2016-05-03-182855.png)

See merge request !171

Modernize AvailableForumsActivity

Turn list of available forums into a `BriarRecyclerView` with XML layout.
Allow to respond to forum invitations from the list of available forums.
The user can either accept or decline an invitation.

![device-2016-05-03-141150](/uploads/0998877d47fb7a3eafe3a90f917d8716/device-2016-05-03-141150.png)

See merge request !172

This changes `ShareForumActivity` to use two fragments to facilitate
forum sharing with the new Forum Sharing Client backend.

The `ContactSelectorFragment` allows the user to select a
number of contacts. If there is an ongoing sharing session or the forum
is already shared with the contact, it is disabled in the list. If there
is at least one contact selected, a button appears in the toolbar that
brings the user to the `ShareForumMessageFragment` where the user can
write an optional message to be send along with the invitation.

After sending an invitation, the user is brought back to the forum that
she shared and there is a snackbar showing up briefly to indicate the
successful invitation.

The invitation is shown along with the message within the private
conversation of each contact. The person who shares the forum also sees
the invitation and the message as outgoing messages that also display
the current status of the messages.

A notification is shown like for other private messages as well.

Please note that this commit does not include a way for users to respond
to invitations.

Turn list of available forums into a BriarRecyclerView with XML layout.
Allow to respond to forum invitations from the list of available forums.
The user can either accept or decline an invitation.

Prevent old forum sharing messages from causing spurious exceptions.