Server console output should be in the log file

In the code there are still a few print statements that are used in different places. Some of them are used to print usage information or errors after checking the input from the command line.

However, there are some print statements used to print, for example, the error message from exception. This usage is fine, but has the problem that those error messages aren't written to the log file. It would be interesting to review that and use the logging library when makes sense so that everything that is needed to troubleshoot a problem is in the log file.

One other case I can think of is the case of an exception being raised and not capture anywhere. In this case, the python's excephook should be replaced with a method that takes care of printing the exception information to both the console and the log file.