Detect first run and initialize database and config

Relates to #1

gui/main.cpp

@@ -1,5 +1,6 @@
 #include <QApplication>
 #include <QSettings>
+#include <QMessageBox>
 #include "mainwindow.h"
 #include "searchresult.h"
 #include "pdfpreview.h"
@@ -9,6 +10,16 @@ int main(int argc, char *argv[])
 {
 	Common::setupAppInfo();
 	QApplication a(argc, argv);
+	try
+	{
+		Common::ensureConfigured();
+	}
+	catch(QSSGeneralException &e)
+	{
+		qDebug() << e.message;
+		QMessageBox::critical(nullptr, "Error", e.message);
+		return 1;
+	}
 	qRegisterMetaType<QVector<SearchResult>>("QVector<SearchResult>");
 	qRegisterMetaType<QVector<PdfPreview>>("QVector<PdfPreview>");
 	qRegisterMetaType<PdfPreview>("PdfPreview");