Updated to include Darkcoin (DRK) pair.

Added the Darkcoin (DRK) and Bitcoin (BTC) pair to MintPal.
Updated Cryptsy to include the NXT pair with Bitcoin and Litecoin.
Merge branch 'master' of https://github.com/Dilgess/BitcoinChecker into Dilgess-master
Added IDs for NXT_BTC and NXT_LTC on Cryptsy