* improved formatting of aircraft views
* extended settings for render restrictions (such as max. aircraft, max range ...)
* connected new signal / slots in runtime
* Doxygen / formatting
* combo boxes, size model changed - fixes the issue with the settings exceeding the boundaries
* main window can be minimized
* renaming the main page
* style sheet
* QFontDialog is not working, as it is affected by the style sheets itself
* Added font settings to the GUI settings tab
* Added font color dialog for fonts
* Several utility methods
