* glom/application.[h|cc]:
* glom/bakery/app.[h|cc]:
* glom/bakery/app_withdoc_gtk.[h|cc]: Move the help menu out of the
Bakery class, doing it all in our derived Application class, to give us
more control over the GtkAboutDialog. We do not need the abstraction any
more.
This restores the application description, which was probably lost when
converting to AboutDialog.