code: function getParentPath(path, sep) {
      if (!is.nonEmptyStr(path))  return false;
      if (!is.nonEmptyStr(sep))  sep = defaultSepChar;
  
      // create new path and remove leading and trailing sep chars
      var properties = filter(path.split(sep), function(elem) {
          return is.str(elem) && elem.length;
      });
  
      // create a parent path
      var parentPath = '';
      for (var i=0; i<properties.length-1; i++) {
          parentPath += properties[i];
          parentPath += (i < properties.length-2) ? sep : '';
      }
  
      return parentPath.length ? parentPath : false;
  }
docs: Given a char separated object path, return the parent part of the path. Given
  a path, return the parent path, for '1.2.3.4', the parent path would be
  '1.2.3'.
  @param {String} path The path for which which we want the parent.
  @param {String} sep The separator character to separate path elements.
  @return {String|Boolean} The parent to the path input parameter or false if there is no parent path.