Nodes on right side of graph aren't centered

[sambonfire]

It looks like the code to center the nodes on the right side of the graph isn't working correctly. For me these nodes were often offset at odd angles. I changed this method to fix it:

        private void CenterTreeToRoot(Node.NodeInputSide side)
        {
            var children = _refTargetNode.GetChildren(side);

            if (children.Count > 1)
            {
                float refTargetY = _refTargetNode.Position.y;
                float size = _refTargetNode.GetLastChild(side).Position.y -
                             _refTargetNode.GetFirstChild(side).Position.y;
                float actualY = _refTargetNode.GetFirstChild(side).Position.y;
                float desiredY = refTargetY - size/2.0f;
                float shiftY = desiredY - actualY;

                for (int i = 0; i < children.Count; ++i)
                {
                    children[i].ForeachChildrenRecursively(side, (node) => node.SetPositionY(node.Position.y + shiftY));
                }
            }
        }

[Begounet]

Hello!

I will completely trust you and add it into the plugin.
I won't tell that I had no idea of what I was doing but I tried to implement an algorithm that I did not fully understood...

So, thanks you for your contribution!
It is now available on master.