Elist implements a cyclic C++ list for
non-copyable objects with an interface similar to
std::list. The list nodes are embeddable and don't
need a common base class, so any object may be
stored inside multiple lists. Furthermore, objects
are automatically removed from their lists on
destruction. No iterator is required to unlink an
element from its containing lists. Elists have
proven to be useful for creating complex object
memory layouts, like scenegraphs or XML trees.
