Update & fix

[papacrouz]

Now nonce can be random or increment by 1 Hashmeter added, works only if the nonce is increment by 1 Fix missing sock & extranonce2 refs

[iceland2k14]

I have a doubt. Which one is Correct blockheader = ctx.version + ctx.prevhash + merkle_root + ctx.nbits + ctx.ntime + nonce or blockheader = ctx.version + ctx.prevhash + merkle_root + ctx.ntime + ctx.nbits + nonce

[papacrouz]

The correct is blockheader = ctx.version + ctx.prevhash + merkle_root + ctx.ntime + ctx.nbits + nonce