superelement

/**
  * @description Groups items from an array into an array of objects, grouped by a property 'prop' name, maintaining original order. Based on functionality of LoDash's 'groupBy' function, but, unlike LoDash, preserves original array's order and returns an array instead of an object.
  * @param arr {array of objects} - Objects within array should contain a property marked by the 'prop' argument, or else they will be excluded from the output and a warning will be logged.
  * @param prop {string} Propery to use for grouping. The value of this will be converted to a string when creating group names.
  */
var groupByKeepOrder = function(arr, prop) {
    var newArr = [] // array to return, keeps track of order
      , wrapObj = {}; // temporary object used for grouping

  _.forEach(arr, function (item) {