#4 minor refactorings

- autoformat
- introduce option to clock recursive method calls
#4 prepare logging

- correct setting needs to be done yet
#2 cover more sort scenarios with UT
#4 change clock format

Numbers are sorted, now. Duration in milliseconds.
(d): 918
#4 show test log per default
Let abstract strategy act as a factory

- make strategy abstract
- provide factory methods for different implementations
- no real factory because I don't want much boiler plate code
#4 minor improvements of log messages
Wanna join the adventure?
remove TODOs
#4 log to file per default