and redo how the curves tool sets its curves in order to support this
without code duplication. Also change the color of the yellow curve in
the dynamics output editor to orange because yellow is hardly visible.
Instead, inherit from GtkBox directly and set the orientation in
init(). Replace more gtk_container_add() by gtk_box_pack_start() in
the reparented classes.
Added two new widgets, GimpDeviceInfoEditor, which is an editor/view
widget for GimpDeviceInfo, and GimpDeviceEditor, which is an editor
widget for all devices. Both are pretty much ugly right now and look a
lot like the old GtkInputDialog, but are at least internally cleaned
up and easily changable code and ui wise. Consider this a completely
intermediate state.
Also cleaned up GimpDeviceInfo so it's possible to have a proper
view on it, and did the needed changes to the preferences dialog
to use the new stuff.
