fix bug 1093237 - move revision diff code into own template macro.

This should also enable the datetimes in the table to take the user's timezone into account.
fix bug 1024649 - add ability to change diffed revisions on translation page
bug 1087015 - Ensure screenshot nav arrows display on tablet on detail page
Bug 1093762: Restore size/space of #search-browse

The search box and the Browse button were nearer in the original design.
They were moved around when the redesign launched.

http://ternowaydesigns.com/wordpress/wp-content/uploads/2012/03/mozilla_demoStudio.jpg
Merge pull request #2897 from darkwing/detail-arrows

bug 1087015 - Ensure screenshot nav arrows display on tablet on detail page
Merge pull request #2889 from openjck/1093762-search-browse-spacing

Bug 1093762: Restore size/space of #search-browse
Merge pull request #2876 from jezdez/bug1024649

fix bug 1024649 - add ability to change diffed revisions on translation page
bug 1093309 - Add Author EULA text to demo detail
Merge pull request #2893 from darkwing/tag-1093309-text

bug 1093309 - Add Author EULA text to demo detail
fix bug 1095004 - Don't show download link on author license demos
Merge pull request #2899 from darkwing/1095004-author-demo

fix bug 1095004 - Don't show download link on author license demos