Fixes #635

Fixes #634

by making it only selectable in detail view

Don't crash if an RSS entry has no date

Closes #641

See merge request !310

Show Blog Posts always in the same design

This also adds comments to the blog post detail screen that were previously missing.
It re-uses the existing `BlogPostViewHolder` and its `bind()` methods effectively reducing the amount of code necessary.

Closes #636

See merge request !307

Add one introduction test for modified response message

This is only the first part of #627, but I am putting it up for review already, since the second part will be very similar and issues found here will likely apply to both.

See merge request !306

Fix view recycling issue with author name typeface

Closes #633

See merge request !305

Merge branch '638-illegalstateexception-when-navigating-out-of-combined-feed-and-back-in' into 'master'

Allow Blog Controller listener to re-attach

Closes #638

See merge request !304

Merge branch '632-badtokenexception-if-rss-error-dialog-is-show-after-activity-is-destroyed' into 'master'

Only show RSS Feed Import Failed Dialog when Activity lives

Closes #632

See merge request !303

Fetch RSS feeds via Tor

This patch replaces jsocks with our own minimal SOCKS 5 implementation, which is compatible with Android's OpenSSL hacks (see discussion on #599 for the horrifying details). This allows us to use OkHttp over Tor to fetch RSS feeds.

It turns out that SOCKS 5 without authentication is a really simple protocol: https://tools.ietf.org/html/rfc1928

Closes #599.

See merge request !308

This also adds comments to the blog post detail screen that were
previously missing.

UI for reblogging and blog comments

This MR wraps all blog posts inside a `CardView` and adds a reblog button to blog posts. When this button is pressed, a new activity opens that shows the blog post again and allows the user to reblog it into their own blog. An optional comment can be added.

Also a new compound view `AuthorView` is introduced to display authors and their trust level in a consistent way.

The `BlogController` has been refactored, so the `FeedController` can share most code through an abstract base class.

![reblog2](/uploads/ce4764851c4cbe39684c95a3b427e3a2/reblog2.gif)

Closes #496, #437 

See merge request !300

Closes #593

Merge branch '605-add-database-method-for-retrieving-a-contact-by-local-and-remote-author-ids' into 'master'

Add database method for retrieving a contact by local and remote author IDs

Closes #605

See merge request !302

Scroll down Adding Contact screen

Normally, you would introduce a new layout only for small screens, but in this case it is easier and has less maintenance overhead to just scroll down the screen, so the button is always visible after loading.

While I was at it, I also replaced `getLocalAuthors()` by the new `getLocalAuthor()`.

Closes #616

See merge request !294

and use it for retreiving the status of an author faster.
Also add tests for both.

Closes #616

Factor out Tor Socks Port

This MR factors out the local Tor port, so other clients can listen to an `TransportEnabledEvent` for Tor and start tasks as soon as Tor becomes available. This would also enable client to pass traffic through Tor's local SOCKS proxy.

See merge request !301

Attach optional messages to invitations in Conversation view

![device-2016-08-29-115823](/uploads/e819324046b8a37ff06da7300046369c/device-2016-08-29-115823.png)![device-2016-08-29-115834](/uploads/051b4b64938bfa6f3ed610db28909865/device-2016-08-29-115834.png)

Closes #359

See merge request !299

Improve conversation screen graphics with less padding

This is how the conversation screen looks with this MR:

![1](https://code.briarproject.org/akwizgran/briar/uploads/3078636c93f7edc6b07034ad808ffc7c/device-2016-08-26-105325.png)
![2](https://code.briarproject.org/akwizgran/briar/uploads/fe0dcd3b1cbc6593aabed6faab1801d7/device-2016-08-26-105425.png)

This MR also replaces more raster graphics with vector graphics.

Closes #352

See merge request !298

Add support for comments and reblogging to Blog Client

Comments and reblogs need to depend on the post they refer to.
Since message dependencies are limited to one group,
the post and also the comments need to be wrapped
when commented on or reblogged to another blog (and group).

For this reason, in addition to comments, two new wrapping message types
are introduced. They retain all data of the original messages and allow
for reconstruction and signature verification.

This MR breaks backwards compatibility with old blog posts.
It removes the content type, title and parent ID from the post.

Furthermore, it includes one commit that replaces the `Message` in `MessageSharedEvent` with a `MessageId`.

Closes #494

See merge request !285

Sign Introduction Information to be able to discover MITM attack

The local introducee doesn't know whether each piece of information received from the introducer originates from the remote introducee or has been replaced by the introducer, i.e. whether the introducer is carrying out a man-in-the-middle attack.

The introduction protocol doesn't aim to detect or prevent man-in-the-middle attacks. We only aim to establish that if the remote identity public key is not replaced then the remote ephemeral public key, transport properties and timestamp are not replaced either. This MR adds a MAC and a signature to the introduction protocol's ACK message to fulfill that aim. See #364 for the detailed security argument.

Later, when the local introducee verifies that the remote identity public key belongs to a particular person (#513), she can also be sure that the remote ephemeral public key, transport properties and timestamp originated from that person.

Closes #364

See merge request !297

Before the introducee sends her ACK,
she derives a master key from the ephemeral shared secret as before.

Two nonces and a MAC key are then derived from the master key.
The local introducee signs one of the nonces and calculates a MAC
over her own identity public key, ephemeral public key,
transport properties and timestamp.
The local introducee includes the signature and MAC in her ACK.

On receiving the remote introducee's ACK,
the local introducee verifies the signature and MAC.
Should the verification fail, an ABORT is sent to the introducer and
the remote introducee that was added as inactive is deleted again.