[v3] Docs for ctype

[Phil Edwards]

> +       /// Typedef for the template paramater

Typo.


> +       /**
> +        *  @brief  Test char_type classification.
> +        *
> +        *  This function finds a mask M for @a c and compares it to mask @a m.
> +        *  It does so by returning the value of ctype<char_type>::do_is().
> +        *
> +        *  @param c  The char_type to compare the mask of.
> +        *  @param m  The mask to compare against.
> +        *  @return  (M & m) != 0.
> +       */

Have you tried running this through 'make doxygen'?  At one point, it didn't
accept @foo keywords after the main description text, but that should be
fixed in any version accepted by run_doxygen, I think.  In any case, it'd be
nice to know that the output is legit and readable before checking that in.

Thanks for doing this.  More docs are always nice.
Phil

-- 
Debugging is twice as hard as writing the code in the first place.
Therefore, if you write the code as cleverly as possible, you are,
by definition, not smart enough to debug it.
    - Brian W. Kernighan