Minor Feature Request: Add alt tag to image in admin bar (accessibility related)

Quick request… swap out

'" style="vertical-align:middle; margin-right:5px; width: 29px; height: 29px" />'

for

'" alt="Performance" style="vertical-align:middle; margin-right:5px; width: 29px; height: 29px" />'

in Generic_Plugin.php.

This will make it so the icon in the admin bar doesn’t trigger accessibility compliance issues while logged into the site.

Thanks for the great plugin!