Creates a new image surface and initializes the contents to the
given PNG file.
Usage
cairoImageSurfaceCreateFromPng(filename)
Arguments
filename
[char] name of PNG file to load
Value
[CairoSurface] a new CairoSurface initialized with the contents
of the PNG file, or a "nil" surface if any error occurred. A nil
surface can be checked for with cairo_surface_status(surface) which
may return one of the following values: