Not yet released
    - when producing Relaxed mode signatures, the partial DKIM-Signature
      header must be canonicalized before hashing (Martin Pool)
      <https://launchpad.net/bugs/587783>

2011-06-14 Version 0.4

    - new API: class DKIM to retrieve domain and other info after verify
    - pydns driver tested and fixed
    - other bug fixes

2008-06-25 Version 0.3

    - length parameter to sign() is now a boolean
    - sign() now folds the DKIM-Signature line
    - validation of all inputs
    - general code cleanup

2008-02-19 Version 0.2

    - handle "rsa-sha1" algorithm properly
    - handle multiple DKIM-Signature lines
    - handle FWS around = in DKIM-Signature lines
    - handle case of single canonicalization algorithm
    - handle l= signature property

2008-02-18 Version 0.1

    - initial release