Stak update - TLS and Nicehash support

New features:

• TLS support (sponsored by an anonymous donor)
• NiceHash support (sponsored by NiceHash)
• Benchmark mode (sponsored by NiceHash)
• Give-up limit
• Pool address is now displayed in the connection report

Fixes:

• Rare divide by zero on an unstable pool

For an AMD graphics card miner please check out
https://github.com/fireice-uk/xmr-stak-amd/releases

DLL files needed to run the release (if you are getting dll errors):
https://www.microsoft.com/en-us/download/details.aspx?id=48145