+DONE: fix unresponsiveness to button events in text edition box (GTK+ 2.17)
+ and segfaults when dragging text or using Layers combobox (GTK+ 2.17)
+DONE: Esc leaves text box if editing; and leaves fullscreen mode
+DONE: package our own copy of the ttsubset library (to remove a dependency
+ on libgnomeprint), and create TT subfonts in memory
+DONE: use gtk-print instead of libgnomeprint