"Statistics" page reworking

[DominicBM]

Several suggestions have been made about the statistics page:

• The "Total" column should only show up for Series, since all others have only one thing being counted.
• For series, move "Total" to right-most column and bold.
• Add some text describing what this is ("These are the top 10 X by number of Y")
• List top items by number of digital objects attached?
• Should file units be counting digital objects as well as items?