Parses the provided WMTS capabilities descriptor and returns the layers of that service.
The layers object passed to the callback is an array of objects with these propierties:
- id: The ID of the layer
- urlTemplate: URL template for the tiles
- zMin: Minimum zoom level of the layer
- zMax: Maximum zoom level of the layer
- zOffset: Offset to z levels of the MapAPI
- bounds: An IWBounds object representing the bounding box of the layer
- opacity: Opacity of the layer (0.6 by default, overwrite to change the opacity)
- title: Title of the layer
- description: Description of the layer
- legend: A legend image