Additionally, remove unused loggers.

* Remove unused code
* Optimize imports (group 10+ and static imports)
* Remove redundant variable assignments
* Replace explicit type parameters with <>
* Remove redundant catch blocks
* Use varargs instead of explicit array instantiation
* Weaken visibility of methods and fields
* Simplify conditions
* Do not use StringBuilder for simple concatenations
* Fix code style
* Remove invalid Javadoc

Updated copyright year and adjusted header format to be consistent over
all files and with other ARSnova projects.

* Organize imports
* Add missing Override annotations
* Remove trailing whitespace

user gets back to the right arsnova