* Remove distinction between "shared with" and "shared by"
* Show all contacts a blog is shared with
* Show online status of contacts in sharing screen
* Add a string label argument to CryptoComponent#hash()
* Convert DoubleDigest from implementing MessageDigest
to implementing org.spongycastle.crypto.Digest
(we need to keep DoubleDigest for FortunaGenerator)
* Convert all other uses of MessageDigest to CryptoComponent#hash()
* Remove CryptoComponent#getMessageDigest(), MessageDigest and DigestWrapper
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
Encode transport properties more compactly in QR codes
The [original BQP spec](https://code.briarproject.org/akwizgran/briar/wikis/BQP) described a compact encoding for transport properties, with the goal of making the QR code as small as possible. At some point during the implementation, I asked @str4d to use TransportIds and TransportProperties instead, as described in the [current spec](https://code.briarproject.org/akwizgran/briar-spec/blob/master/protocols/BQP.md). That was a mistake.
Using the original format reduces the payload from 60 to 34 bytes (43% smaller) for Bluetooth only, and from 96 to 49 bytes (49% smaller) for Bluetooth and LAN. This makes it easier to scan codes from low-resolution screens using fixed-focus and/or low-resolution cameras. Using this branch I can exchange codes between the Sony Xperia Tipo (320x480 screen, fixed focus, 640x480 preview size) and the Huawei Ascend Y300 (480x800 screen, infinity focus, 1280x720 preview size).
This also removes an obstacle to implementing #558, as TransportIds are no longer included in QR codes.
Closes#346.
See merge request !394
