A Swift subclass of NSImageView for loading remote images asynchronously.
- Download images from the Web to DKAsyncImageView asynchronously with just 1 line of code
- Set a 'Placheholder Image' to be displayed until the image is downloaded
- Set an 'Error Image' to be displayed when an error occurs while downloading the image
- Set ToolTips for each state -> Loading Image / Image Loaded / Error Loading Image
- Display a Spinning Wheel on top of DKAsyncImageView while it's downloading the image