- A command line tool to interact with Sequoia.  Useful for
    debugging and development.

  - Subpackets are returned to users, and are only useful if the
    content is readable.

  - Improve the documentation.

  - Re-export 'openpgp'.

  - Re-export the other crates without prefix.

  - The partial_body module is only used by parse.  So, this is the
    right place.

  - Also, there is now no reason for body_length_new_format to be
    public.  So, make it private.

  - Most callers won't actually have a `BufferedReader`, so giving the
    nice name to this interface doesn't make sense.  Also, the new
    name is more consistent with PacketParser and PacketParserBuilder.

  - Update users.

  - `Message::from_reader` already accepts an object implementing a
    `std::io::Read` interface.

  - Update users of `Message`.

  - To make it easier to understand what the PacketParser is doing,
    add an option trace its execution.

  - Add a setting to the PacketParser to enable buffering of unread
    content when the PacketParser is advanced.

  - Fix how the amount of data to consume is computed in
    BufferedReaderMemory::data_consume.

  - To support the easy propagation of multiple settings and their
    clear separation from the other state, bundle all settings in a
    struct.

  - Consider:

      impl<R: io::Read> Foo<R> {
          fn from_reader(reader: R) -> Foo<R>;
          fn from_file(file: File) -> Foo<File>;
      }

    A caller can't invoke 'Foo::from_file(file)', because the compiler
    doesn't know how to make R concrete (even though R isn't used!).
    So the caller has to do: Foo::<Type>::from_file.  But, we can do:

      impl Foo<File> {
          fn from_file(file: File) -> Foo<File>;
      }

    And then callers can do: Foo:from_file.

  - Currently, the max_recursion_depth parameter is passed to the
    PacketParser constructor.  Since this should not normally be set,
    and to prepare for additional parameters, use the builder pattern.

  - Given a PacketParser, it is possible to read() the content.  If we
    only read part of the content and then call recurse(), recurse()
    will probably fail to parse the packet.  Forbid this at compile
    time.

  - It is still possible to recurse manually by calling
    PacketParser::from_bytes on the content, as shown in the test
    case.

  - Remove nom from the list of dependencies.

  - The only thing that was using nom was the ctb parser.  But,
    manually taking the byte apart is straightforward (and takes fewer
    lines of code).

  - Add some tests to exercise the ctb parser.

  - Put the parser in a separate impl.

  - Provide convenience interfaces for parsing a TPK from a reader and
    a file.

  - Prefer the PacketParser interface where possible.

  - Extend test suite to exercise both the Message-based parser and
    the PacketParser-based parser.

  - Add some more asserts to the test suite.

  - Test data is no longer kept next to the source code to keep the
    code cleaner.

  - Rename foo.asc to foo.gpg when the file contains binary data and
    not ASCII armored data.

  - Rename literal-mode-t-partial-body.txt to
    a-cypherpunks-manifesto.txt, since this is the source for several
    files and not only literal-mode-t-partial-body.gpg.

  - 9db72f10 make the fields of the
    different packet structs public as well as the Message and
    Container structs.  These shouldn't be made public; these
    structures should be accessed via their accessor methods.

  - There are two sensible iterators for Messages and Containers:
    iterate over the children and iterate over all descendants (i.e.,
    a depth-first traversal).

  - Rename iter() to descendants, provide children() and rename
    into_iter() to into_children().

  - Provide the same interface for Containers.

  - Change Message to contain not a vector of packets, but a
    Container.

  - Check that the user id is correct.

  - Demonstrate changing the network policy instead of the home
    directory.  This is more robust.

  - The network policy determines how Sequoia connects to remote
    servers.

  - Add a policy field in the context.

  - Add an error indicating a policy violation.

  - Honor the policy in the net module.

  - Add ffi glue.

  - Move the 'example.c' to sequoia-ffi.

  - Fix and improve Makefile.

  - Instead of implementing iter() for individual packet types, just
    implement it on PacketCommon.  The Deref implemenation for Packet
    will take care that Packet.iter() works.

  - Make sure the content was consumed.

  - To allow packets to be streamed, implement the Read and
    BufferedReader interfaces for PacketParser.

  - Add and use Result and Error type.