PNG Lib?

[dsimcha]

Is there any simple PNG lib that's:

1.  Written in pure D.

2.  Licensed under the Boost or zlib/libpng license, or some other license
that is open-source, non-copyleft and doesn't require binary attribution.

3.  Small enough that I could just copy/paste it into my Plot2Kill lib and
give credit, thus avoiding dependency hell?

4.  Doesn't necessarily have the best features or compression ratio in the
world.  The compression ratio just has to be decent and the features just have
to include writing an array of pixels to a PNG file.  I don't need anything fancy.

I've got extracting pixels saving to .bmp files working in the DFL version of
Plot2Kill and, though GDI is inherently raster based and vector formats will
likely never be supported under DFL, I think the DFL version could be
considered decent if it at least supported PNG out of the box, instead of just
horribly wasteful BMP.  However, I don't want to force users to install yet
another dependency in addition to DFL and Plot2Kill, possibly one that
requires having a C compiler conveniently available.