* app/actions/documents-commands.c
	* app/actions/file-commands.c
	* app/dialogs/file-open-dialog.c
	* app/dialogs/file-open-location-dialog.c
	* app/display/gimpdisplayshell-dnd.c
	* app/widgets/gimplayertreeview.c
	* app/widgets/gimptoolbox-dnd.c: replace % with space
	in file name before showing error message,
	fixes bug #162147.

	* app/core/gimp-gui.c
	* app/widgets/gimpmessagebox.c: be a bit more paranoid
	about validating utf8 for messages.