[#17] Get most viewed datasets from Solr instead of database
[#17] Update readme for new most-viewed-datasets behaviour
Merge branch '17-mostviewed-from-solr' into next
[#11] Capitalise first letter in search 'order by' lists
[#11] Changed 'viewed' to 'most viewed' in search 'order by' lists.

Change ascending/descending for title to a-z/z-a.
Merge branch 'next' into resource_formats