Flash Messenger fixes for PHP < 5.4, and fix for default namespacing

## Overview
Flash Messenger view helper is broken for less than PHP 5.4; this is due to the use of a closure and utilize the variable $this.  The fix for that was to ensure that we could just use the variables.

Secondly when one attempts the utilize the view helper using the defaults much like you add a message inside of the controller
```php
$this->plugin('flashMessenger')->addMessage('foo');
```

Then you should be able to get that value similarly in the view like:
```php
$this->plugin('flashMessenger')->render();
```