* docs/tutorial/C/index-in.docbook: Update the FileChooser section.
* examples/book/buildapp/step5/exampleappprefs.[cc|h]:
Use the Gio::Settings::find() overloads with mapping functions,
if available.
* examples/book/headerbar/examplewindow.[cc|h]: Use AlertDialog
instead of MessageDialog.
* examples/book/listbox/examplewindow.cc:
* examples/book/range_widgets/examplewindow.cc: Use std::array.
* examples/book/recent_files/examplewindow.[cc|h]: Use FileDialog
instead of FileChooserDialog.