proposed srfi for extended character sets

[Tom Lord <lord@xxxxxxx>]

Ok, I've written up a proposed srfi on recent topics.  Hopefully it
will pass the editor-test and appear soon enough.

I took out all of the controversial stuff (e.g., O(1)
recommendations).

I took out all of the non-essential stuff (e.g., the \U+... syntax).

I simplified the set of new procedures I think are needed.

Hope you'll like it.

-t