Feature/add people tool

This includes changes for displaying member count for each section, on the page that displays the list of sections. The UI has also been modified to reflect the count.(As of now all the enrollees will be displayed. If there are people having 2 roles within a section, they will be counted separately. If it's determined that this needs to change, additional filters could be applied, but the  base method would still remain the same)
I missed it in the other review, but could it make sense to give the includeStudentsFlag a default value of False so that you don't need to explicitly pass False in the common case?