Document i18n features of Forrest

There is next to no documentation about i18n, just a pretty poor FAQ entry that points at an issue that has now been closed.

Cheche wrote a blog entry on his work:

http://casa.che-che.com/blog/2005/05/10/internalization-a-site-using-forrest-07-dev/

We could, at the very least use the locationmap to pull this content into our site [OT: I wonder if this could be a way to generate more documentation?)