code: function ValidationErrors(errors) {
    this.errors = errors ? errors : {};
  
    this.addError = function(field, message) {
      if (!this.errors[field]) { this.errors[field] = []; }
      this.errors[field].push(util.format(message, field));
    };
  
    // omit field for full hash of errors
    this.getErrors = function(field) {
      if (field) {
        return this.errors[field];
      } else {
        return this.errors;
      }
    };
  
    this.hasErrors = function() {
      return _.keys(this.errors).length > 0;
    };
  
    this.isValidationErrors = function() {
      return true;
    };
  }
docs: errors is a hash of name -> errors