Add MakeUnique (substitute for C++14 std::make_unique)
Add MakeUnique (substitute for C++14 std::make_unique)

From @ryanofsky:s #10973. Thanks!

chaincoin/chaincoin,chaincoin/chaincoin,chaincoin/chaincoin,chaincoin/chaincoin,chaincoin/chaincoin,chaincoin/chaincoin