please make ntsa::SocketOption::print() output include option type

[lxv]

ntsa::SocketOption so1;
so1.makeLinger();

ntsa::SocketOption so2;
so2.makeZeroCopy();

std::cout << "so1=" << so1 << std::endl;
std::cout << "so2=" << so2 << std::endl;

outputs:

so1=LINGER[ enabled = false duration = (4829128, 21860576) ]
so2=0

If the first line of the output is actually useful to convey the option type and its value, the 2nd line is not so much. I suggest you always include both option type and the value in the string representation of ntsa::SocketOption values.