Added new score manager (mdw) command.

Description: (mdw) rewrites the __metadata__.py module in any package.

Metadata ordered dicts now format like this ...

    tags = collections.OrderedDict([
        ('forces_tagline', 'for six players'),
        ('title', 'Red Example Score'),
        ('year_of_completion', 2013),
        ])

... instead of like this ...

    tags = collections.OrderedDict([
        ('forces_tagline', 'for six players'),
        ('title', 'Red Example Score'),
        ('year_of_completion', 2013)])

... which harmonizes metadata storage formatting and system default storage
formatting.

If you (mdv) a metadata module and the module uses old-style formatting, then
you can (mdw) to cause the metadata module to rewrite with new-style
formatting.