fixed performance regression for Ethash/Etchash algorithm on Nvidia miding edition cards
added auto-tune for Ethash/Etchash algorithm on Nvidia cards, miner automatically select fastest kernel, also you can select specific kernel manually by using --oc flag, currently 3 kernels available, 0 means auto-tune by miner
added display of shares per minute
added option to control hashrate report interval (--report_interval in seconds)
removed cuckarooz29 algorithm due Grin will not support it after hardfork