Fix layouting (isPlaceHolder should be isPlaceholder)
codeeditor: multiSelectJump, cycles through multi-select ranges. By default CMD+Shift+> and CMD+Shift+<
morphic/debugging: make sure that "show" rectangles also work for / in "fixed" morphs
morphic/images: new setImageURL interface, allowing to constrain extent + async API. Usage:

var morph = lively.morphic.Image.fromURL(
  url, {maxHeight: 50},
  function() { show("loaded and resized!"); })
lively.presentation: make sure presentation can exit