onRenderModule event

One use case: Allow developers to include a module chrome outside of /templates/TEMPLATE/html/modules.php

If a developer is deploying a framework that powers all of their templates, and a module chrome is persistent across these templates, the opportunity to include a module chrome path within their framework (Joomla! plugin), instead of having the same file or same chrome declarations ship with every single template helps tremendously with maintenace/upgrades.

Also exposes $module and $attribs.

Notes:
The code comes directly from the T3 Framework repository. They override JModuleHelper with a copy of the core file and include this change.
https://github.com/t3framework/t3/blob/master/source/plg_system_t3/includes/joomla30/modulehelper.php#L234