PK_ERROR_code_t PK_EDGE_euler_merge_vertices
(
--- received arguments ---
PK_EDGE_t       edge,   --- Edge to delete
PK_VERTEX_t     vertex  --- Vertex to delete
)


This function deletes an edge by merging its vertices.


Specific Errors:
    PK_ERROR_edge_not_open          edge is not open
    PK_ERROR_no_common_vertex       edge is not incident with vertex


vertex will be deleted while the other vertex of the edge will survive.  The
edge must be open.

It is possible that edge is the only one incident with either of its
vertices: if this is the case then the result is an isolated vertex.

Any geometry attached to edge and vertex will be deleted and the resulting
body will normally be invalid.

The inverse of this function is PK_VERTEX_euler_split