Tables integrated hierachically

'Module_table' is part of 'Class_table'

'Class_table' is part of 'Feature_table'

	modified:   ocaml/class_table.ml
	modified:   ocaml/class_table.mli
	modified:   ocaml/context.ml
	modified:   ocaml/context.mli
	modified:   ocaml/feature_table.ml
	modified:   ocaml/feature_table.mli
	modified:   ocaml/term_table.ml
	modified:   ocaml/typer.ml