added mix hash to block header
added mix hash to block header

jmgilbert2/energi,jmgilbert2/energi,RyanLucchese/energi,rsdevgun16e/energi,jmgilbert2/energi,RyanLucchese/energi,rsdevgun16e/energi,rsdevgun16e/energi,RyanLucchese/energi,RyanLucchese/energi,jmgilbert2/energi,jmgilbert2/energi,RyanLucchese/energi,rsdevgun16e/energi,jmgilbert2/energi,RyanLucchese/energi,rsdevgun16e/energi,rsdevgun16e/energi