Home Page Overlay: Fixed # Recently Published Items

Up to 9 recently published items should be rendered if the screen
resolution is approximately 1920x1080 or better, otherwise no more than
6 should display. Bug caused no more than six to render no matter the
resolution.
Auto-Start Tours WIP

Still need to handle if overlay click is same URL, etc.
Auto-Start Tours WIP

Switching to GUID. Tour entity to be passed to mechanism that runs tours
is populated but needs some kind of extension from tour.js with extra
non-entity values. Need to research.

Also need to handle if same collection as displayed.
Auto-Start Tours Completed

Can now link to and auto-start a tour from a URL by having
@auto-tour={the tour GUID} at the end of the URL, where the part before
the @ consists of a link to the root timeline of the collection that
contains the tour. This includes launching a tour in a different
collection to the one currently displayed. See /featured/featured.json
for an example. (ChronoZoom's introductory tour.)

The Intro Tour link on the home page overlay now remains present, even
when on collections other than the Big History collection.

The ChronoZoom Introductory Tour has been added to the default featured
content list so there are now 7 items. We hope to add two more featured
content items (totalling nine) in the near future.
Merge branch 'master' into improvements
Fix to Run on Azure

Azure requires correct parameter list inside comment text.
Merge branch 'NeilCresswell-improvements'