Split AdManager.tallySlave into two functions, one which does the actual...

Split AdManager.tallySlave into two functions, one which does the actual tallying for the report, and a free function which counts the categories in which a slave matches a facility's ads.

Remove AdManager from everywhere that doesn't actually need to keep a slave tally state, and just use App.Ads.getMatchedCategoryCount everywhere the persistent state is not needed.  This means only App.Ads.report actually needs an AdManager instance, which cleans things up quite a bit.