Description:
    The filter generator creates stubs for a new filter.

    The generator takes a model name as its argument.  The model name may be
    given in CamelCase or under_score and should not be suffixed with 'Filter'.

    The generator creates a model class in app/filters and a test suite in
    test/unit/filters.

Example:
    ./script/generate filter RDoc

    This will create a RDoc filter:
        Behavior:   app/filters/r_doc_filter.rb
        Test:       test/unit/filters/r_doc_filter_test.rb

