Minor changes for the iOS port.
More work on the logging.
Use more Cocoa-friendly init names.
Use SVGKImage getters in the image rep as opposed to SVGKSource subclasses.
Make it so that the image rep privately can have the anti-alias, curve flatness, and interpolation quality set.
Have SVGKImage take advantage of the image rep's new properties in exportNSImageAntiAliased:curveFlatnessFactor:interpolationQuality:, but fall back to getting the NSBitmapImageRep if there was a problem with SVGKImageRep.
Get rid of the custom code in SVGKImage's NSImage getter: just rely on exportNSImageAntiAliased:curveFlatnessFactor:interpolationQuality:.
Minor change to get copy to work correctly.