gtk_drawing does not exit properly

[Gerritv]

When gtk_drawing is used as graphics in combo with gui_internal on N8x0 (and others), the Close window button (x in top RH corner) closes the window but not the application. this patch adds signal_connect for delete_event and related function to handle the tidy close of Navit. Tested on N8x0 and x86/Ubuntu

[Spaetz]

Thanks, applying would be great. I get bitten by this with navit on the OpenMoko

[KaZeR]

Applied in rev2009, minus the Makefile part. Thanks for your patch!