Change logging framework to Logback and provide autoconfiguration

[stephanr]

Change the logging framework from log4j2 to Logback by providing a deegree module that provides configurators for Logback.
This is done by registering a java style deegree default configurator class beside the regular Logback file-based configurator.

So if no Logback configuration was added to the war or configured with a system parameter or environment variable, the deegree auto configurator kicks in and configures console- and file-logging as well as the levels.

This is not yet finished, as the documentation is work in progress and the default settings are not final yet.

TODO:

• provide section about using a different logging implementation

fixes #1248
closes #1705

References:

• Reevaluate the use of log4j within the deegree project #1248
• Create new module deegree-core-test-logging, add test-logging dependencies and remove log4j2.properties in test modules #1704
• Change logging framwork from log4j2 to logback #1705

[tfr42]

Also relates to issues #1782 and #1251.

[julianzz98]

I tested the PR locally and can confirm the described functionality. If no logging configuration is set at startup, the autoconfiguration is applied. Once a logback.xml file is added to /usr/local/tomcat/webapps/deegree-webservices/WEB-INF/classes, the specified logging configuration is used.

Nevertheless, /usr/local/tomcat/webapps/deegree-webservices/WEB-INF/classes still contains a log4j2.properties file, which can be removed.

[stephanr]

As discussed in todays tmc meeting this log4j.properties file has to be removed in this PR as well https://github.com/gritGmbH/deegree3/blob/b8d6ceb3f28f6e40b476d420a7a35ac3e25dccaf/deegree-services/deegree-webservices/src/main/resources/log4j2.properties
I will add this for the next tmc meeting