used tidy-html5 to clean up html

Hi!

After a bit of research a while back, I found that It's actually possible to have tidy leave the ```<i></i>``` elements intact! (this is good, as tidy was driving me insane for a while there...)

The key is specifying ```drop-empty-elements: no``` in the config file or on the command line.

You can see the config file I used here: https://gist.github.com/paultreny/9822049

Don't have to accept the pull request if you prefer to tidy it yourself, but thought I'd share anyways!