Fix Phobos dependencies on autodecoding

[Argolis]

On Thursday, 15 August 2019 at 19:05:32 UTC, Gregor Mückl wrote:
> On Thursday, 15 August 2019 at 11:02:54 UTC, Argolis wrote:
>> [...]
>
> This is the point we're trying to get across to you: this isn't 
> sufficient. Depending on the context and the script/language, 
> you need access to the string at various levels. E.g. a font 
> renderer needs to sometimes iterate code points, not graphemes 
> in order to compose the correct glyphs.
>
> [...]

I want to thank you, that's was really inspiring to me in trying 
to dig harder in the problem!