- Update `Cargo.lock` to get the latest and greatest.  In
    particular, buffered-reader 1.1.4 and sequoia-openpgp 1.13.0.

  - Require chrono 0.4.23 or newer, not exactly 0.4.23.

  - Enable static linking, which Android and iOS builds prefer.

  - See PEMA-103.

  - Fix deprecations.

  - Don't use the `rust-toolchain` file to specify the version of
    `cargo` and `rustc` to use.  Instead use `rust-version` in
    `Cargo.toml`.

  - Note: this changes how we choose the tool chain: `rust-version` is
    a minimal version; `rust-toolchain` is an exact version.

  - Use 1.60 as that is what is currently available in Debian testing.

  - Closes #7, #10.

  - The repository has moved to the pEp.foundation organization.
    Update the URL.

  - Add a function to copy a slice to a C pointer and length.

  - Use it.

  - Add macros to check that pointers are not NULL, to turn a pointer
    and length into a slice, to turn a C string into a `CStr`, and to
    interpret an OpenPGP fingerprint as a `Fingerprint`.

  - Use them.

  - If `PepIdentity::as_mut` is passed a NULL pointer, return an error.

  - Change `rust_str_to_c_str` and `rust_bytes_to_c_str_lossy` to
    return a `Result`.

  - Return `Error::OutOfMemory` if `malloc` fails instead of undefined
    behavior.

  - Update the callers to propagate the error when convenient and to
    panic explicitly when not.

    - Note: Rust panics if a memory allocation fails so we don't go
      too far out of the way to propagate memory allocation errors.

  - Add a struct, MM, which holds the malloc and free implementation
    passed to pgp_init_.

  - Pass it to all functions that allocate using malloc or free memory
    using free.

  - enumber 0.3 has been released.  It is no longer necessary to use
    an unreleased version.

  - Instead of using the cookie in the Session data structure to point
    to the Keystore, point to a struct.

  - This makes it possible to have additional state.

  - stringpair_t and stringpair_list_t will be needed by the
    implementation of pgp_list_keyinfo.

  - Add the GPL v3 to COPYING.

  - Fix the stale package config template.

  - Always generate it when building.

  - What cargo wants, cargo gets.