Milestone 3.x progress

Finishes

1. #115 (closed)
2. #127 (closed)
3. #131 (closed)
4. #132 (closed)
5. #136 (closed)
6. #138 (closed)

backend/main/java/de/griefed/serverpackcreator/ApplicationPlugins.java

@@ -25,13 +25,11 @@ import de.griefed.serverpackcreator.plugins.serverpackhandler.PreGenExtension;
 import de.griefed.serverpackcreator.plugins.swinggui.TabExtension;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
-import org.apache.logging.log4j.core.util.FileUtils;
 import org.pf4j.*;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.stereotype.Component;
 
 import java.io.File;
-import java.io.IOException;
 import java.util.List;
 
 /**