Cleaned up a lot of code; Modified the visual appearance of the GUI itself; Removed bugs; Added some localization strings; Updated the flow editor; replaced the checkstyle config file with the newer one from the Kieker project; Removed a lot of unnecessary comments to make the code easier to read

This reverts commit 8fd2a615.

Updated the kieker-jar and some other dependencies; Added the user-properties; Some code-modifications for quality reasons; Refactoring