cpuminer-opt-3.19.8

#370 "stratum+ssl", in addition to "stratum+tcps", is now recognized as a valid url protocol specifier for requesting a secure stratum connection.
The full url, including the protocol, is now displayed in the stratum connect log and the periodic summary log.
Small optimizations to Cubehash, AVX2 & AVX512.
Byte order and prehash optimizations for blake256 & blake512, AVX2 & AVX512.