Adds HTML5 semantics to notifications

Notifications view was using all divs for breaking up sections, this
commit adds HTML5 semantic markup to better describe content sectioning.
Adds splash image to background on contact view

Adds a splash image to the background of the contact view. Also adds a
gradient overlay to fade the image into the solid background.
Merge pull request #96 from codeforamerica/92-photo-in-contacts

92 photo in contacts