v0.21

        Fix test failure with Carp 1.32 where CARP_TRACE is called on mocks.
        Copy Devel::PartialDump code into the distribution with changes:
         - Removed Moose dependency
         - Removed all functions (only dump() remains as a method)
         - Minor bug fixes:
            'list_delim' attribute is now used to separate lists.
            'max_length' attribute with value 0 now dumps '...'.
            Object dumps have '=' after the class name.