Fixed PNG plugin so it handles endianess correctly, and alpha/grey scale textures.
Fixed PNG plugin so it handles endianess correctly, and alpha/grey scale textures.


marchelbling/osg,tomasthoresen/osg,openscenegraph/osg,artoolkit/osg,jtorresfabra/osg,scrawl/osg,jtorresfabra/osg,scrawl/osg,tomasthoresen/osg,jtorresfabra/osg,marchelbling/osg,marchelbling/osg,jtorresfabra/osg,artoolkit/osg,openscenegraph/osg,scrawl/osg,openscenegraph/osg,tomasthoresen/osg,marchelbling/osg,scrawl/osg,openscenegraph/osg,artoolkit/osg,tomasthoresen/osg,artoolkit/osg