Add Intersection
It can happen that more than one point is placed, despite describing the same intersection.
This usually happens when several partys work on the data individually.
This button can be used to merge these points into one.
Usually there will be one point that is positioned more accurately than the other.
First click on the point that has been placed less accurately.
Then click on 
Now click on the point that has been placed accurately.
The program will merge the two points and transfer all the information liked to the two points.
