* allow to send status message to main window (from everywhere)
* Use sGui::changedStylesheet where possible
* message when model is stashed
* improved application startup
* invalid models can be highlighted on stash
* selection mode can be toggled between single/multi selection (where applicable)
* color for highlighting can be set
* finetuning of menus
* added required signal slots
* moved models for stashing into aircraft model view
* allow to unselect when stashed
* fixed DB object highlighting and resize row height automatically
* use incremental updates
* use new signatures
* handle successfully published models
* some custom menus are gone, because they are now part of the specialized views
* renamed to connectDataReadSignal
* removed unused individual signals, e.g. vatsimMetarsRead -> replace by data read signal + entity flag
* added data in METAR class (kept there, not in airspace monitor) -> reader aware
