Keep the completed skull from hiding the + sign

[deadjakk]

When you're working with a large tree and you begin marking trees containing branches as complete, you can no longer see the + sign that indicates subtrees as the skull seems to clobber/hide the symbol, consider instead, making it only prepend the skull. In addition, consider making it so that the plus sign and skull symbols do not cover the first part of the node text. Instead of covering the text, have it prepend the node text.