[Csv] Dialect passing...

[Andrew McNamara]

Just to throw the cat amongst the pigeons, it occured to me that my
logic for making the dialect a instance rather than a dict was slightly
bogus: the inheritance can still be done with a dictionary, simply by
copying it:

excel = { 'delimiter': ',' }

excel_tab = excel.copy()
excel_tab['delimiter'] = '\t'

That said, the instance approach looks a little more natural to my eye.

-- 
Andrew McNamara, Senior Developer, Object Craft
http://www.object-craft.com.au/