Fix: removed 'open Type'

The module 'type.ml' does not exist anymore

	modified:   ocaml/assertion_table.mli
Added the module 'Option'

	modified:   ocaml/container.ml
Added some more syntatic types

	modified:   ocaml/class_table.ml
Added signature maps to find features

	modified:   ocaml/feature_table.ml
	modified:   ocaml/feature_table.mli