[9] Review request for 8033534 Get MultiResolution image from native system

[Alexander Scherbatiy]

Hello,
Could you review the fix:
  bug: https://bugs.openjdk.java.net/browse/JDK-8033534
  webrev: http://cr.openjdk.java.net/~alexsch/8033534/webrev.00

- The method that gets a sorted array of NSImage representaion pixel 
sizes for the given image size is added
- A MultiResolution image is created if an NSImage has several 
representations for the given image size

Thanks,
Alexandr.