[1/5] windowscodecs: Implement QueryCapability in the PNG decoder.

[Vincent Povirk]

>> For JPEG and TIFF, which are extensible formats, there's also the
>> possibility that an image has something in it that we don't support
>> (and that the corresponding decoder on Windows doesn't support) but
>> some other decoder on the system can.
>
> A not supported stream format is a bug and should be fixed IMO. I believe
> that an implementation which declares support for all formats is better
> than a not implemented stub.

I'm not sure. There are plenty of standard TIFF files that native
can't handle (though I don't think it's a bug if we can), and there's
the possibility of non-standard TIFF files that a corresponding
third-party decoder can.