docs: function loadJSON( path ) {
      return new Promise( function( resolve, reject ) {
          var xhr = new XMLHttpRequest( {
              mozSystem: true
          } );
          xhr.onload = function() {
              var text = xhr.responseText;
              try {
                  resolve( JSON.parse( text ) );
              } catch ( ex ) {
                  reject( Error( "Bad JSON format for \"" + path + "\"!\n" + ex + "\n" + text ) );
              }
          };
          xhr.onerror = function() {
              reject( Error( "Unable to load file \"" + path + "\"!\n" + xhr.statusText ) );
          };
          xhr.open( "GET", path, true );
          xhr.withCredentials = true; // Indispensable pour le CORS.
          xhr.send();
      } );
  }