Replace all System.out.prinln(...) with proper logging

[nileger]

Problem

Currently, we create a lot of log output using System.out.prinln(...).
Unfortunately, we can't control whether System.out.println should be logged or not with any property (in comparison to using a proper logger).

Solution

Replace all System.out.prinln(...) with proper logging as in T2PControllerHelper.class;
Logger logger = LoggerFactory.getLogger(T2PControllerHelper.class);
logger.debug("Instantiating the WorldModelBuilder ...");
Then, by setting the log level in application.properties, we can control what is being logged.