Add the ability to define default kwargs for the MARKUP_FILTER

[GoogleCodeExporter]

Currently it's only possible to define initial settings using 
settings.MARKUP_FILTER for a non-
named markup filter. It would be good if I can define initial settings for all 
markup filters in a 
simple way like:

{{{
    MARKUP_FILTER = {
        {'markdown':
            {'safe': True}
        },

        {'restructuredtext': {
             {'settings_overrides': {'header_level': 1, 'other_option': 2 },
             {'writer_name': 'html4css1' }, 
        }
        ...
    }
}}

However this might break the scheme as it always rely on django. 

{{{
    ``MarkupFormatter`` behaves this way so that it can be used
    stand-alone, without the need to configure or even install
    Django.
}}}

Original issue reported on code.google.com by mar...@mahner.org on 14 Apr 2009 at 4:59