Improve the L&F of the notification emails

See attached screenshots.

Issues:

• Too narrow viewport, should take more width
• The application type in the left gutter takes quite a lot of horizontal space, reducing the space for the details
• The separation between the list of users who have modified the page and the details is not clear.

Ideas:

• Maybe we should have some config options for the mail so that the user can choose whether to see the details or not (and if not have a link to the wiki to see the details maybe, for ex on "edited by ..."). If the wiki is quite used or if we page is heavily modified, it might generate a very long list of details. We could also limit the details to 5 items and then have a link to point to the wiki.
• Another idea: display a blame/annotated view of the changes (ie display last author who changed a line as in the code view)