Improve coverage templates

* Force index.html url (usefull for access with file:///local/path/to/coverage type of access)
* Switch percent and class name to have percents aligned and improve human comparaison
* Add monospace font to file listing
* Update CSS

![code coverage of duplic at](https://cloud.githubusercontent.com/assets/932553/2561000/6211b404-b7f5-11e3-8fa4-5945d5e3b6f1.png)

![duplic at code coverage of duplicat backuper](https://cloud.githubusercontent.com/assets/932553/2560999/53878364-b7f5-11e3-84d0-40757bf2780a.png)