Added to OP new exchange https://poloniex.com/exchange/btc_cure

Added to OP the start of the public ledger that will eventually be displayed on curecoin.info.
https://docs.google.com/spreadsheets/d/10YF2W9Iwbn77ybCsj5Lxqa_Dzvo6WedbRGBwoBOrm3k/edit#gid=0