Update ISC License to 2007 version

    Before accepting the license as a free software license, the
    Free Software Foundation (FSF) asked for clarification of the
    text. In July 2007, as a result, "and distribute" was changed
    to "and/or distribute".

                      -- http://en.wikipedia.org/wiki/ISC_license

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>