Implemented _attribute_manifest on inventory classes.
Updated Tuning doctest.
Implemented Selector.make_inventory_class_selector().

Example:

    >>> selector = iotools.Selector()
    >>> selector = selector.make_inventory_class_selector()
    >>> result = selector._run()

    Select:

        1: ClefInventory
        2: MarkupInventory
        3: OctaveTranspositionMapping
        4: OctaveTranspositionMappingInventory
        5: PerformerInventory
        6: PitchRangeInventory
        7: TempoInventory
        8: TimeSignatureInventory

    > q
Cleaned up Editor.__init__().
Removed _target_class property from Editor.

Editor is now always initialized with a target.

Use type(editor.target) instead of editor._target_class.
Removed _target_class from AttributeManifest.
Cleaned up MaterialPackageWrangler.

Removed unused data package creation methods.
Cleaned up MaterialPackageWrangler._make_main_menu().
Cleaned up MaterialPackageWrangler.

Removed MaterialPackageWrangler._make_managermade_material_packge().

Use MaterialPackageWrangler._make_material_packge() instead.
Cleaned up MaterialPackageWrangler.
Cleaned up MaterialPackageWrangler._get_material_package_manager().
Cleaned up MaterialPackageManager.write_output_module().
Extending MaterialPackageWrangler.

MaterialPackageWrangler.make_material_package_for_editable_mainline_class()
is almost complete.
Updated TODO.
Updated TODO.
Updated TODO.
Reactivated MaterialPackageManager material summary menu section test.
Cleaned up MaterialPackageManaer._make_material_summary_menu_section().
Consolidated material package manager _has_output_material_editor() methods.
Updated TODO.