Configure server for serving osgjs files

It's more efficient to serve gzip files instead of plain text / binary files. In order to have the browser un gzip files correctly you need to adds custom header on your server for .gz files.

example of what I use with nginx:

        location ~ \.gz$ {
                gzip off;
                add_header Content-Encoding 'gzip';
                default_type text/plain;

                add_header Access-Control-Allow-Origin *;
                add_header Access-Control-Allow-Credentials 'true';
                expires 31536000;
                add_header Cache-Control public;
        }

The alternative is to include the gunzip.min.js in your html files then osg will fallback to gunzip in js. This solution is less performant than the server header.