* garrigues/union_find/self_dual_reconstruction.hh,
	* garrigues/union_find/self_dual_reconstruction.cc: Add a new version
	of self dual reconstruction.
	* garrigues/union_find/Makefile: New, Add a simple Makefile.
	* garrigues/union_find/canvas/find_root.hh,
	* garrigues/union_find/canvas/reconstruction_on_function.hh,
	* garrigues/union_find/canvas/reconstruction_on_set.hh,
	* garrigues/union_find/canvas/self_dual_reconstruction.hh: Move
	find_root implementation in find_root.hh.
	* garrigues/union_find/images/marker.pbm: Rename as...
	* garrigues/union_find/images/marker_to_erode.pbm: ...this.

git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@3198 4aad255d-cdde-0310-9447-f3009e2ae8c0