Add missing foreign key and output fatal dbconn error as alert.
Fix reading datetime/timestamps from database
Clean up student/search results.

Now there is a SectionSession class to handle a database Session object.
Has a function to join Session objects in an array that have the same weekday.
Added search for Positions by professor name
Position apps now use Bootstrap alerts to show errors

Fixed a bug causing Event logging of STUDENT_APPLY to emit E_NOTICE,
causing a JavaScript/AJAX call error in search.js

Fixed a bug where non-students viewing student/search.php would see a
blank page or PHP error instead of a clean TARS error alert.