Add option to set minimum value of accepted work
Add option to set minimum value of accepted work

If the available work is not above some minimum value, put the miner to
sleep.
Also, changed the total value display to use the already calculated
value in the pubkeybatch_t.

sobakasu/vanitygen,enlighter/vanitygen,enlighter/vanitygen,sobakasu/vanitygen,WyseNynja/vanitygen,WyseNynja/vanitygen,Cremator/vanitygen,Cremator/vanitygen,sobakasu/vanitygen