Add standard translations

Hi Russell,

Long time no see – have you fallen completely off the grid? ;-)

I have added a small feature – a railtie – to load built-in translations automatically when using in a Rails project. Then you can just set `I18n.locale`, and it will automatically use the right translations for miscellaneous characters, HTML entities, and vulgar fractions for that particular language.

I have added the English and Danish languages and also included the standard Danish transliterations of Æ, Ø, and Å. (Maybe this should replace pull #95?)

Ok, hope you can use it. :)

Thanks,
/Lasse

PS. If you decide to merge this into master, we need to find a way to test it. Some standard way of testing a railtie, using a Rails dummy app or so?