Mark to be removed triangles when using Fix_single_connec_edge_elements.m

[cnske]

When using the Fix_single_connec_edge_elements class once can set a parameter how aggressive this triangles get removed.

It would be great if the class can get an option so that one can see which triangles will be removed. In that way it can be possible to adjust the shapefile beforehand and omit unnecessary removal.

Maybe it could also be possible to select which one to keep or any other option how to take care of them.