Add some additional functions for stats to stats.py script.
This included getStudents, getUsers, getMentors, getOrgAdmins, countStudentsWithProposals and some style fixes.
Patch by: Pawel Solyga
Reviewed by: to-be-reviewed
<html>
<head><title>We ran out of memory</title></head>
<body>
We ran out of memory while serving your request, please try again.
</body>
</html>