[Radiant] Snippet hierarchy

[Maurizio Balestrieri]

Working on mostly multi-lingual web sites, I'm finding it would be
very useful to be able to organize snippets in a hierarchical way as
we do for pages. For example every time I need a navigation menu
snippet, I need to have it separated for the English language and the
Italian one. The same goes for footers, headers, etc. At the time
being I'm simply naming them like: "header_it", "header_en", etc. But
when you have more languages, and/or several design layouts for the
same site (which therefore requires to maintain multiple headers,
footers, etc.: e.g. "header_reboot_it", "header_reboot_en", where
"reboot" is a different layout which requires a different snippet
content) it could quickly become difficult to deal with a fairly long
sequential list of snippets. --M