/*!

\page free_faces_page Free faces

This mesh quality control highlights the faces connected to
less than two mesh volume elements. The free faces are shown with a
color different from the color of shared faces.

\image html free_faces.png

In this picture some volume mesh elements have been removed, as
a result some faces became connected only to one
volume. i.e. became free.

\sa A sample TUI Script of a \ref tui_free_faces "Free Faces quality control"
operation.

*/