Constraints tab was a bit messy, it contains 10 icons for 3D shapes constraint and another 5 for the 2D ones. Right now they are more compact and are using just 10 icons to display the tools. Also are more logical in the sense that they are grouped by shape.
Other improvement was the Point to Point constraint. When you worked to Point To Point constraint you have to pick the two points that you want to constraint, and you will have in property grid the distance between those points you've selected and you can change it. Anyway, if you selected by mistake twice the same point, the constraint will not apply or you may not notice that the tree was changed previously. For this reason, there is a nice addition that it will be shown a dimension arrow to let you know that the constraint is well defined by user actions. Also the action was extended in case you picked two points from the same shape. If you pick two points from different shape, the propagation will move the destination shape to be separated on the distance you've just setup. On a similar way, Point to Point constraint, on the same shape will scale your current shape to keep strict the distance you did chose.
In this way for example when you will edit your rectangle's width, to keep the distance just as needed, the rectangle will scale accordingly, letting your original width as chosen, so there are cases when does not behave just as you expect. If you want a really fixed width, you have to pick the Rectangle's width constraint, not Point to Point one, which is much more generic.