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
