Refactored assemble.hpp, now three parts: select_rings, assign_parents, add_rings

Rewritten ring_properties 
Obsoleted add_to_containment.hpp, assemble.hpp

[SVN r69510]

libs/geometry

@@ -1 +1 @@
-Subproject commit 520f6ffa001045a5d8028a4cfda9b550a96895e8
+Subproject commit 2fcbf1c7c95d4effd923dcbe57c16b1fea769e3e