add libqhull recipe.
add libqhull recipe.

Qhull is a general dimension convex hull program that reads a set of
points from stdin, and outputs the smallest convex set that contains
the points to stdout.  It also generates Delaunay triangulations,
Voronoi diagrams, furthest-site Voronoi diagrams, and halfspace
intersections about a point.

vmayoral/beagle-ros,vmayoral/beagle-ros,vmayoral/beagle-ros,vmayoral/beagle-ros