[net] Improve the information for socket properties

[cuiyanx]

Description

Please Improve the information for socket properties.

// Socket properties
    Number bufferSize;    // Size of read buffer
    Number bytesRead;     // Total bytes read for the socket
    Number bytesWritten;  // Total bytes written for the socket

Those are undefined.

Test Code

Simple test:

console.log("socket.bufferSize:", typeof sock.bufferSize, sock.bufferSize);
console.log("socket.bytesRead:", typeof sock.bytesRead, sock.bytesRead);
console.log("socket.bytesWritten:", typeof sock.bytesWritten, sock.bytesWritten);

Steps to Reproduction

Actual Result

Expected Result

Be defined.

Test Builds

Branch	Commit Id	Target Device	Test Date	Result
master	8a5bafc5	Arduino 101	May 18, 2017	Fail

Additional Information

[grgustaf]

This is really an enhancement, part of the Node.js API we haven't supported. This would require extra bookkeeping and I don't think it's of great value to the app developer in this environment, so I'm also lowering the priority.