New network protocol, speed improvements

I added a new binary based protocol similar to Stratum, called
'x.pushthrough'. Compared to the previous getwork() implementation it
reduces traffic by more than 90% and number of connects per minute by
98%. It has some other nice features which will be described in detail
in the coming specification.

I also started to tweak some OpenSSL functions to get more speed, the
miner should be about 20-30% faster now.