Release Name: 0.23

Notes:



Changes:
  "nodes" are now "memos"
  brand new treeview selection logic in place
  improved about dialog, added license info and visit-homepage button
  added line drawing option
  changed homepage url
  sketch bottom-right parts are now cropped for fast loading (switchnode-saving got slower but switchnode-loading got faster)
  added squared line drawing
  made treeview expanders work
  "new sketch node" / "new text node" menuitems unified into one "new node" menuitem