Tweak the nearby preview

* Move heading out of header
* Make the preview only show first paragraph and show the page image
* Make the listThumb class more generic so it can be used in
the preview
* Update retrievePage to allow access to lead section only

Change-Id: I372d76d54b48f50c2aeb614bc34c0ed1e9f8a033
Merge "Tweak the nearby preview"