We have a lot of stuff that needs to behave differently in a development

environment than in production. We initially conditioned all of these on

the DEBUG setting, but a lot of users tend to turn that on when they

encounter problems, and then sometimes forget that they did so.
On the Review Board side, we've moved these things behind a new settings

key, PRODUCTION. This allows people to set DEBUG = True and get more

thorough logging, while not completely breaking their system. This

change brings that same key to Djblets.

Ran unit tests.
Smoke tested extension template loading.