Addition of function which will compute the parameter bounds of a curve given a surface. This will by default be the same value as returned from parBounds except when the edge is degenerated: then it will have different bounds on each surface. This is what now is going wrong while meshing a periodic surface with a degenerated edge on multiple surfaces. As by default meshGeneratorPeriodic is called for each periodic surface (instead of only periodic surfaces on the seam), this surface is now checked on the uv-coordinates to see whether the edge loop is closed. As the parameter bounds of the degenerated edge on its second surface is incorrect, the loop is found to be open and thus an error occurs.