Used tokens with arguments

In order to do the lexing with nested comments an entrypoint with
argument is used. The argument indicates the nesting level of the
comments. Using an argument of the entrypoint avoids a global
variable.

	modified:   ocaml/lexer.mll
Removed obsolete files

	deleted:    library/kernel/abstract_sequence.e
	deleted:    library/kernel/any.e
	deleted:    library/kernel/array.e
	deleted:    library/kernel/boolean.e
	deleted:    library/kernel/function.e
	deleted:    library/kernel/predicate.e
	deleted:    ocaml/boolean1.e
	deleted:    ocaml/test.e
Preparation to parse only the usage block of a a source file

	modified:   ocaml/eiffelc.ml
	modified:   ocaml/lexer.mll
	modified:   ocaml/parser.mly
Splitting of strings added to 'Container'

	modified:   container.ml
Added string sets and string maps

	modified:   ocaml/container.ml
Focussed beta reduction activated

	modified:   ocaml/proof_context.ml
	modified:   ocaml/proof_table.ml
	modified:   ocaml/prover.ml