code: function prepare ( data, useQs ) {
  	var ret;
  	if ( !('FormData' in global) || useQs ) {
  		ret = qs(data);
  	} else {
  		ret = new FormData();
  		for ( var prop in data ) {
  			if ( data.hasOwnProperty(prop) ) {
  				ret.append(prop, data[prop]);
  			}
  		}
  	}
  	return ret;
  }
docs: @param  {Object} data
  @param  {Boolean} useQs
  
  @return {String|FormData}