* glom/application.cc: set_progress_message(): Set the main UI elements to
insensitive(), because all our current uses of the progess message should
block user input, like a modal dialog.
* ui/operator/window_main.glade: Move the InfoBar out of the frame, because
it should not have the border, and so we can make the frame insensitive
without making the InfoBar insensitive. This required adding an extra
intermediate GtkBox, because otherwise there is no way to add the menubar
at the top, before the InfoBar.
This .glade file needed some hand-editing to remove bad <packing> tags that
glade (from git master) added.