cn/gpu algo support

Added support for cn/gpu algo (new RYO algo)

cn/half algo support

Added support for cn/half algo (new MSR/XTL algo)

ARM fixes

Fixed build stuff for non Intel/AMD platforms.

More robust cn/2 asm usage detection

Added more robust Cryptonight/2 PoW assembler detection.

Accelerated cn/2 support

Added Cryptonight/2 PoW assembler implementation support.

Final fixed cn/2 support

Added Cryptonight/2 final tweak PoW support.

cn/2 support

Added Cryptonight/2 PoW support.

xmrig 2.6.4

Added TUBE/XAO/RTO PoW support.

ARM support

Added ARM/ARM64 arch support.

xmrig 2.6.3

Added support for Cryptonight (MSR) and Cryptonight-Heavy (XHV) PoW types.