[R6RS] string escapes

[dyb at cs.indiana.edu]

> there is sight opposition to additions like \n and \t.

I would ignore the opposition to \n and perhaps a few other similar
escapes.

>  \x<X...>
>
> in strings and symbols and
>
>  #\x<X....>
>
> for characters, where the "<" and ">" are literal and "X" stands for a
> hex digit.

This seems fine with me.

> Of course, if we escape delimiters, we could use Scheme syntax for
> numbers, as suggested before. But I like the simplicity of hex-only
> combined with the readability of escape delimiters.

I agree.

Kent