* configure.in: require Gtk+ 2.14 and VTE 0.17.1

	* src/gnome-genius.c, src/graphing.c, ve/ve-miscui.c: fix some
	  sealing things.  Do note that we do not yet compile even without
	  deprecated stuff since gtkextra is full of it.  Also use some newer
	  things that required gtk+ 2.14 and vte 0.17.1

	* src/graphing.c: fix zooming in 2D plots when moving mouse
	  in any direction.