BUG: Admin jobs page locks up due to backend/database problems

[albertyu03]

Summary
When there is a problem with the database, the Manage Jobs page locks up and becomes unusable.

Expected Behavior
The Manage Jobs page should show some sort of error message to the user in response to database errors, or otherwise handle the problem in a way that is easier to debug.

Current / Observed Behavior
When there is a problem with the database, the Manage Jobs page locks up. Nothing can be clicked or accessed.

Steps to Reproduce
Log into Happy Cows as an Admin user.
Navigate to the Manage Jobs page.
If there is an issue with the backend, the Manage Jobs page will lock up within a few seconds of opening.
Browser / Platform Info
Chrome, Safari