Incorrect termination of connectionHandlingThread

[igor-sladkov]

In verson 2.3.2
CS104_Slave_stop doesn't wait for whether connectionHandlingThread has terminated, when it's closing open connections and destroying threads. MasterConnection_close just clears isRunning flag then returns immediately.
After that connectionHandlingThread will not complete properly, connectionEventHandler will never be called and a socket will be in a waiting state.
It would be better to implement execution control of connectionHandlingThread, as is done for serverThread.
The stopRunning flag should be used as a request to terminate connectionHandlingThread in all cases instead of isRunning, including inside handleTimeouts (but better to replace it with "timeoutsOk = false;"). Waiting for thread termination (isRunning==false) might be added to MasterConnection_close.