[GH-3] Fix logging with agents

[DaGeRe]

Currently, logging doesn't work with the agents, since logback isn't part of the distribution. We should fix this somehow, from my point of view, there are two options:

• Include logback in the agent (rendering the custom logging of all systems under monitoring unusable)
• Change all logging inside of the agents to something isolated of the logging framework
• Publish kieker-aspectj-log4j, kieker-aspectj-logback, ...

I think the first one is the easiest solution, if there is a real use case, we can go for the third option.

[DaGeRe]

Also evaluate: Can we add the logging framework to the agentpath?