Fixed error in Firefox, switched to FileReaderSync in WorldLoader Worker.
Fixed error in Firefox, switched to FileReaderSync in WorldLoader Worker.

b-z/terramap.github.io,TerraMap/terramap.github.io,b-z/terramap.github.io,hanleybrand/terramap.github.io,hanleybrand/terramap.github.io,TerraMap/terramap.github.io