Make GitVersionCheckCJM handle Git::Wrapper 0.028_96

  Don't pass Path::Class objects to Git::Wrapper
  Bump dist & GitVersionCheckCJM version to 4.13
Add $api_version to MakeMaker::Custom get_prereqs

  Fix compatibility with Dist::Zilla 4.300032
  Add extract_keys_as_hash to Dist::Zilla::Role::HashDumper
Add TestRequires to mb_custom.t
Updated Changes for April 4, 2013 release of 4.13