Add equals to Rectangle
Add ol.ImageUrlFunction
Add ol.Image class
Add ol.layer.ImageLayer
Add ol.source.ImageSource
Add ol.renderer.canvas.ImageLayer
Add containsExtent to ol.Extent
Add scale to ol.Rectangle
Add ol.source.SingleImageWMS
Add ol.source.StaticImage
Add FIXME to ol.control.Attribution
Add ol.renderer.dom.ImageLayer
Add ol.renderer.webgl.ImageLayer
Use an ImageLayer in wms-custom-proj example
Rename ol.Rectangle scale to scaleFromCenter
Do not sort resolutions array

We assert that the resolutions array is sorted instead of sorting it ourselves. This is to consistent with ol.TileGrid.
Make ol.Image emit change events
Avoid busy-waiting while images load

This is to be in conformance with the work done with #184.
Test the image layer renderer's transform matrix
Deal with null images