add comment back about fixing About dialog crash... I got a crash again, but I don't usually get one
make dialogs "always on top" for now, to prevent them disappearing under GTK_FILE_CHOOSER dialogs (N.B. this is not a new bug - it occurs with the old GTK_FILE_SELECTION dialogs too)
better fix: make all dialogs (I think, except encoding progress dialog) correctly transient to prevent them disappearing under GTK_FILE_CHOOSER dialogs (N.B. that the logic of many of the dialogs should be improved: no or cancel buttons and what happens after you click them)