* improved formatting of aircraft views
* extended settings for render restrictions (such as max. aircraft, max range ...)
* connected new signal / slots in runtime
* Doxygen / formatting
(!) This in an intermediate step, the feature is not yet fully operational
* max distance for rendering as simulator property
* set max distance / aircraft from GUI
As result of the latest meeting
* changed CCallsignList to CCollection
* fixed some warning with elevated compiler settings (e.g. removed qint values -> int)
* preparation for a context menu to send text messages from ATC/aircraft view
* preparation for context menu for fast pos. updates
* reverse ICAO lookup at login screen
* display fast updates / parts in GUI
* moved max- aircraft into settings
* made serverselection own component
* 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
