ARSD PNG memory usage

[Guillaume Piolat via Digitalmars-d-learn]

On Tuesday, 16 August 2016 at 16:40:30 UTC, Adam D. Ruppe wrote:
> On Tuesday, 16 August 2016 at 16:29:18 UTC, Guillaume Piolat 
> wrote:
>> Hey, I also stumbled upon this with imageformats decoding PNG. 
>> Image loading makes 10x the garbage it should.
>> Let's see what this threads unveils...
>
> leet me know how it is now

Reverted back to a stb_image translation to avoid the problem 
altogether (though it's a bit slower now). Rewriting offending 
allocations in std.zlib was harder than expected.