A D port of utf8proc

[MrSmith]

On Saturday, 11 April 2020 at 23:36:17 UTC, Ferhat Kurtulmuş 
wrote:
> I could not find a similar library working with -betterC, so I 
> ported utf8proc.
>
> https://github.com/aferust/utf8proc-d
>
> Please test it, contribute it, and enjoy!

in readme this expression is wrong: `(mstring.sizeof / 
ubyte.sizeof) * mstring.length`
should be `mstring.length` instead