Libpng...

Work is progressing in integrating libpng...

I come out with a better algorythm to draw the cached chunks. Right now it works, but when you zoom out/in to a different "zoom level" it will cause a reload of all the nine chunks, which is SLOW. I want to change so that at any time it load only a few chunks (the visible ones). This will cause more reloads while you pan, but it should be faster on average...

Update: i finished implementing the libpng reader, it works, but maybe some more testing can be useful.

Update: i rewrote the chunk management code in LayerMap, it seems to be faster, i am testing it right now!