code: function getLog(logFn, marker) {
  	var result = pLog
  	result.log = logFn = logFn || appData.log
  	result.marker = marker
  
  	return result
  
  	function pLog() {
  		logFn(marker + ' ' +
  			util.format.apply(this, Array.prototype.slice.call(arguments)))
  	}
  }
docs: /*
  Get a log function that prepends marker
  logFn: optional function default appData.log, log function with util.format capability
  marker: string: what is prepended to each log invocation
  
  return value: function with properties
  .log: the underlying log function
  .marker: the marker string