* New vertices are successfully created in the intersections between the
curve and draw surface triangles
* New vertices are also inserted along the bottom edge of the filled curve.
* However, new vertices will still need to be inserted in the lines connecting the
top of the curve and the bottom where they intersect with the triangles.
* The option for filled curves remain hidden in the GUI. See #2860.
# Please enter the commit message for your changes. Lines starting
