Test on abstract::pset alternative code for static inheritance. 
	
	* oln/core/abstract/entry.hh: New proposition for entry class in
	static hierarchies.  This is a test file that should be removed
	after stc update.
	* oln/core/typedefs.hh (fixed_type, ra_type, bbox_type): New
	typedef declarations.
	* oln/core/abstract/bbox.hh (fwd_piter_, bkd_piter_): Remove
	these forward declarations.
	(ext_vtype): Remove.
	(vtypes): New.
	(ra_type, fixed_type, bbox_type): New associated types.
	(bbox): Change inheritance from abstract::pset to an entry class.
	(bbox): Remove all methods except print from this class; the
	methods are dispatched into abstract::bboxed_pset and
	gen::bbox_<P>.
	(bbox): Likewise for attributes.
	(print): Reject code to subclasses.
	(impl_bbox): New method.
	* oln/core/abstract/pset.hh: Include entry.hh.
	(fwd_piter_type, bkd_piter_type): New associated types.
	(bbox_type, ra_type, fixed_type): Likewise
	(pset): Add virtual to inheritance.
	(~pset): Extend check code.
	(fixed_pset, ra_pset, bboxed_pset): New sub-abstractions.
	(pset_fixed_hierarchy, pset_ra_hierarchy, pset_bboxed_hierarchy):
	New hierarchy tags.
	* oln/core/gen/bbox.hh: Update.
	(operator=): New.



git-svn-id: https://svn.lrde.epita.fr/svn/oln/trunk@522 4aad255d-cdde-0310-9447-f3009e2ae8c0