Log Message:
Update p5-MooseX-Types-Structured to 0.28.

Changes from previous:
0.28   03 October 2011
        - Fixed regression where mixed type constraints (MX:Types style and
        'classic' Stringy style) are used in a single structured type doesn't
        work.

0.27   28 April 2011
        - test fixes for new Moose

0.26   02 January 2011
        - removed version from Test::Fatal as asked by the debian folks
        - small documentation updates

0.25   28 December 2010
        - fixed bug where ->is_subtype_of dies meaninglessly when the type we
          are trying to check is not a type we can find.  This makes our
          handling consistent with core Moose.  Also changed ->equals and
          ->is_a_type_of to be consistent.
        - Added test case for above
        - The test suite now uses Test::Fatal instead of Test::Exception (Karen
          Etheridge).

0.24   16 November 2010
        - Added some performance enhancing caching code (phaeton)