Shakemaps failing when crossing the international date line (IDL)

When an event occurs close to the international dateline (180˚E/˚W) the target site model and resulting shakemap cannot be built.

There are several steps to solving this problem:

1. OpenQuake site models require longitudes in the range -180˚E to 180˚E, so permit bounding boxes to generate limits beyond -180˚E and 180˚E in order to generate the site models, but then translate sites in the range long < -180˚E and > 180˚E accordingly. This would make it possible to calculate the ground motions for the sites.

2. For exporting to raster there are two options: i) Split the raster into two different rasters (one either side of the IDL), ii) translate the sites back so that longitudes can be outside of the -180˚E to 180˚E band and retain the simple bounding box shape.

@nils and @eggi - what is the preferred approach for EarthExplorer in this case? Split the raster into two rasters or tolerate longitude values < -180˚E and > 180˚E