function warn_deprecation(message, untilVersion) {
	  console.warn('Deprecation: ' + message + (untilVersion ? '. This feature will be removed in ' + untilVersion + '.' : ' the near future.'));
	  console.trace();
	}
Wrap the contents of a text node to a specific width

	  Adapted from bl.ocks.org/mbostock/7555321

	  @author Mike Bostock
	  @author Dan de Havilland
	  @date 2015-01-14