adding `campus` layer to cohorts
updating the answer_set searching to include campus grouping
adding campus adminstrators and tweaking some of the `accessible_object` methods
adding display of commenter name for cohort admins (and adding commenter cohort for everyone)
hiding cohort name from comments if only one cohort is selected in the filter
altering the lable on the cohort filter field
adding some padding to tables
adding `name` to users and enabling editing of users by admins
checking for nully values (like `n/a`) in comments after saving... and removing them if found
removing extraneous lines from cohorts_controller - since it's using
correcting typo in the campus model
correcting typo in cohorts form
adding crud for campuses
grouping cohorts on the answer_sets#index filter by their campus (if there's more than one campus to show). Also filtered out past cohorts by default.
tweaking the application menu links
tweaking abilities for campus admins
adding `new relic` gem
moving chart-data calculation to model methods
moving default filter cohort_ids to user model, and showing expired cohorts if there's none currently running
bug in abilities, and in the calculation of accessible_cohorts. also tweaking the accessible_answer_sets method - as it doesn't return correctly for campus admins