Features:

  - Automatic, periodic garbage collection of local cache entries older than
    the maximum cache age.
  - Ability to purge the local cache via client API and front-end.
  - Approximate local cache size can be retrieved via the client API and
    front-end.

Enhancements:

  - Unify client endpoints to `127.0.0.1:8077` (HTTP proxy) and
    `127.0.0.1:8078` (front-end) by default and enable both by default.
  - Update readme to remove obsolete information and better help testing.
  - More efficient URI swarm name computations.
  - Use newer OpenSSL library.
  - Use a non-dummy version number in the client API, and have proper release
    notes. `;)`

Bugfixes:

  - Avoid issues with BitTorrent bootstrap nodes resolving to an IPv6 address
    first.
  - Avoid the agent from furiously retrying when there is no fresh mechanism
    available.
  - Other fixes for Android and asynchronous operations, timeouts and
    cancellations.

This unifies endpoints used by the client in the different current scenarios:
standalone binary, Docker container, Android library.

Now the default HTTP proxy endpoint is `127.0.0.1:8077`, and the default
front-end endpoint is `127.0.0.1.:8078`, with both enabled by default.

The reason for `127.0.0.1` and not something less prone to clashes like
`127.7.2.1` (as we do in the injector) is that the client is expected to run
on many platforms (while we can assume GNU/Linux for the injector), and not
all of them support binding to addresses in `127.0.0.0/8` other than
`127.0.0.1` (e.g. macOS and other BSD-based systems).  Thus it becomes more
reasonable to choose a less crowded port (8077 and the following one in this
case).

Documentation and other references in code and other files have been updated
as well.

This contains many updates to the readme file for removing obsolete
information and better help test the technology.

The injector does not seed the content, the client does.

The file will be updated before tagging the new version (along with other
release-related files like `Dockerfile`).

Since they match the defaults, do not set them explicitly using client
options (but keep the code commented out in case this is needed later on).

The rationale for using `127.0.0.1` with a less common port is the same than
that for the client proxy endpoint new default.  The particular port is just
the one following the proxy port, which is still quite uncommon.

Also use `localhost` instead of `127.0.0.1` when talking about agent proxy
configuration, reserve use of the IP to client and injector configuration.

Do not override it in the example configuration file.

This was already the default in Docker-based clients.

The reason for `127.0.0.1` and not something less prone to clashes like
`127.7.2.1` (as we do in the injector) is that the client is expected to run
on many platforms (while we can assume GNU/Linux for the injector), and not
all of them support binding to addresses in `127.0.0.0/8` other than
`127.0.0.1` (e.g. macOS and other BSD-based systems).

Thus it becomes more reasonable to choose a less crowded port (8077 in this
case).

127.0.0.1 -> 127.0.0.137 (to be less standard and so avoid clashes)

And removed V1 prefixes and suffixes from the rest of the storage code.

Use `/logfile.txt` instead of a query string to ease saving it or opening it
in some text viewer or editor.

Instead of closing the connection, as that prompted the UA to furiously
retry sending the same request many times.

It was causing crashes on Android

This adds several enhancements for HTTP store maintenance:

  - Removal of entries older than `max-cached-age`, as well as temporaries not
    seeing progress.
  - A periodic garbage collector for such entries.
  - Removed entries are no longer announced in the DHT.
  - Reporting of (approximate) local cache size in the status API and client
    front-end.
  - A button to purge the local cache in the client front-end.
  - Cancellable local cache iteration and cleaning operations.