update_perspective without actual edits, bypassing the full state assignment protocol;
edit_nodes/Perspective: do not touch_descendants here;
propagate editor scroll events via update_perspective;
misc tuning;
#contributed components
contrib/cvc3-2.2
contrib/e-1.2
contrib/kodkodi-1.2.16
contrib/spass-3.7
contrib/scala-2.8.1.final
contrib/vampire-1.0
contrib/yices-1.0.28
contrib/z3-2.19