Update from version 0.74 to version 0.75.

Upstream changes:
0.75 Mon, April 20, 2009
    * Moose
    * Moose::Meta::Class
      - Move validation of not inheriting from roles from Moose::extends to
        Moose::Meta::Class::superclasses (doy)

    * Moose::Util
      - add ensure_all_roles() function to encapsulate the common "apply this
        role unless the object already does it" pattern (hdp)

    * Moose::Exporter
      - Users can now select a different metaclass with the "-metaclass"
        option to import, for classes and roles (Sartak)

    * Moose::Meta::Role
      - Make method_metaclass an attr so that it can accept a metarole
        application.  (jdv)

(seb)