logic: file associations for Mac and opening project files via Mac OS

* hide start screen when opening with project file
* added project icon file to bundle and file type association to plist
* listen for file open events from double click or drag and drop
* fixed crashes in window handling

src/lib_gui/qt/QtApplication.cpp

@@ -0,0 +1,30 @@
+#include "qt/QtApplication.h"
+
+#include <QFileOpenEvent>
+
+#include "utility/file/FilePath.h"
+#include "utility/messaging/type/MessageLoadProject.h"
+
+QtApplication::QtApplication(int& argc, char** argv)
+	: QApplication(argc, argv)
+{
+}
+
+// responds to FileOpenEvent specific for Mac
+bool QtApplication::event(QEvent *event)
+{
+	if (event->type() == QEvent::FileOpen)
+	{
+		QFileOpenEvent* fileEvent = dynamic_cast<QFileOpenEvent*>(event);
+
+		FilePath path(fileEvent->file().toStdString());
+
+		if (path.exists() && path.extension() == ".coatiproject")
+		{
+			MessageLoadProject(path.str(), false).dispatch();
+			return true;
+		}
+	}
+
+	return QApplication::event(event);
+}