Use -[NSObject isMemberOfClass:] to get classes that are exactly what we're looking for.
We are targeting 10.7 and later. The warning about missing functionality isn't needed.
Trim down the use of preprocessor ifdefs in SVGSVGElement.m by defining NSStringFromCGRect to NSStringFromRect on OS X.
Change the way SKSVGObject's "unimplemented" methods are handled: send the message to NSLog, and tell Objective-C we don't recognize that selector.
Include the proper header.
Use modern syntax to init a mutable dictionary in CALayerExporter.