Add Google TileLayers

[ThePieMonster]

The below are the URLs for the Google Tile Layers that are not present in the tile layers list in UMap currently. It would be great to see these added, especially a satellite view as there are currently no proper satellite view options.

List

Roadmap http://mt0.google.com/vt/lyrs=m&hl=en&x={x}&y={y}&z={z}

Terrain http://mt0.google.com/vt/lyrs=p&hl=en&x={x}&y={y}&z={z}

Altered roadmap http://mt0.google.com/vt/lyrs=r&hl=en&x={x}&y={y}&z={z}

Satellite only http://mt0.google.com/vt/lyrs=s&hl=en&x={x}&y={y}&z={z}

Terrain only http://mt0.google.com/vt/lyrs=t&hl=en&x={x}&y={y}&z={z}

Hybrid http://mt0.google.com/vt/lyrs=y&hl=en&x={x}&y={y}&z={z}