Add support for NBMiner for ETH mining.

[dialmaster]

Add the ability to run NBMiner from dmo-wrapminer (for ETH mining monitoring)
NOTES:
To Start NBMiner with rest api use: --api 127.0.0.1:13013 (eg, host:port)
To access stats:
http://127.0.0.1:13013/api/v1/status

Stats should be passed on to dmo-monitor in exactly the same way they are for dmo mining.
All other functionality should remain in place/as-is.
I can re-use "MinerOpts" to pass additional command line options to NBMiner.