title: QT: socket notifiers cannot be enabled from another thread
body: <p>I have a QTcpSocket and I need to control it - write + read using multiple threads.</p>
  
  <p>This works fine in QT4 but in QT5 I am getting this error and it seems that only 1 thread has access to socket at a same time. How do I make it possible for a socket to be accessed by multiple threads?</p>
  
  <p>Basically I want to create 1 thread for reading and 1 thread for writing of data, so that I can asynchronously read and process the data while doing something else in rest of application.</p>
  
  <p>Note: answer to <a href="https://stackoverflow.com/questions/16895989/qt-handle-qtcpsocket-in-a-new-thread">Qt - Handle QTcpSocket in a new thread</a> doesn't help here, because it describes how to transfer socket from thread 1 to thread 2 and then use it from thread 2 only. I need to use it from both threads.</p>