Changes in version 0.3.1:
- Don't output garbage on NSS errors.

Changes in version 0.3:
- New packet formats that only encrypt the secrets, not all metadata,
  potentially allowing to unwrap the secret directly into a hardware crypto
  token.
  The new default format (both for volume_key(8) and the Python bindings) is
  LIBVK_PACKET_FORMAT_ASYMMETRIC_WRAP_SECRET_ONLY.
- Update to compile against cryptsetup-1.1.0-test0.
- Support newer libblkid versions.

Changes in version 0.2:
- New Python bindings.
- Terminating NUL is not considered a part of the secret in
  libvk_volume_add_secret ().
- When an UI callback is replaced, the previous callback data is freed.
- Minor bug fixes, mostly in the command-line utility.
- Stricter parameter checking.
- README added.
