Add support for NiceHash compatibility

[rumplin]

Add support for NiceHash compatibility.

There are some pools that are NiceHash compatible, they offer a separate port for mining with NiceHash.

https://www.nicehash.com/compatible-pools

"If you are a pool operator and would like to be added to our list of compatible pools Contact us."

Don't know actualy what it means to be NiceHash compatible.

On NiceHash you can verify if your mining pool is ok:

Algorithm: DaggerHashimoto

Resolving pool host somepool.com... OK
Establishing connection with proxy... OK
Establishing connection with pool IP:PORT... OK
Sending mining.subscribe... OK
Sending mining.authorize... OK
Received mining.notify subscription... OK
Received authorization result... OK
Received mining.set_difficulty... OK: difficulty=0.93130836
Received mining.notify work... OK