Optimize (and fix) /manage/statistics queries

[willgearty]

Many of the queries on the /manage/statistics result in errors or take a long time. I'm guessing we aren't being nearly as optimal as we could be for some of the DB queries that we make. We should do the following:

• Test existing queries to see which ones don't work
• Check the code for the existing queries and make sure they are as optimal as possible (only grab the data we actually need)
• Add paging if we are going over a large number of programs
• Add caching, if possible (to improve loading of the page during periods of stasis)