* Added call to the SkinTemplateToolboxEnd hook, as per MonoBook.php et al.
* Coding style (quotes, variable names) cleanup
* Comment cleanup -- removed an useless, incorrect comment I had copy-pasted from Vector.php
* Fixed default $wgRefreshedHeader['img'] to be valid HTML -- an <img> element must have an alt attribute, even if said attribute would be empty, in order to be valid HTML