Add jsoncpp dependency for solidity-js.
Add jsoncpp dependency for solidity-js.

arkpar/solidity,ruchevits/solidity,LianaHus/solidity,chriseth/solidity,ruchevits/solidity,gluk256/solidity,ruchevits/solidity,debris/solidity,shahankhatch/solidity,chriseth/solidity-doc-test,ruchevits/solidity,douglas-larocca/solidity,ethers/solidity,LefterisJP/solidity,vaporry/solidity