Show UnsavedDocumentsDialog when closing window or quitting application

so user can save and or discard docs more efficiently.

pglab/CMakeLists.txt

@@ -34,6 +34,9 @@ set(PGLAB_SOURCES
     querytool/QueryExplainModel.cpp
     querytool/QueryParamListController.cpp
     querytool/QueryTool.cpp
+    querytool/SqlDocument.cpp
+    querytool/SqlDocumentRegistry.cpp
+    querytool/UnsavedDocumentsDialog.cpp
     serverinspector/DatabasesPage.cpp
     serverinspector/RolesPage.cpp
     serverinspector/ServerInspector.cpp