Changed U/X of map nodes with locked position
When you move a node on the map, its position is locked so that its position is no more dynamicaly calculated based on others. You could notice a locked node based on the black stroke.
You didn't? Yes... I felt like it. And Nicolas suggested an improvement.
So now, a small lock is displayed aside the locked node, with a tooltip telling you how to unlock the node position :) The ctrl+click unlock stills work, but you can also simply click on the lock.
Cheers!