added calls of move cunstructor for returning string values.
added calls of move cunstructor for returning string values.

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