Improvements: Support for Google Earth. Configuration files splited.

- New administration for Google Earth map and layers
- New Google Earth map type (basic map with no extra options for now)
- New KML layer type (KML is generated at http://localhost/mapigniter/googleearth/kml/1 where 1 is the GE Map ID)
- New Google Earth layout module
- New Google Earth search module
- When creating map with "auto" option, also creates Google Earth map and layer