Add new TEMPLATES setting.

Review Request #8709 — Created Feb. 3, 2017 and submitted — Latest diff uploaded

Information

Review Board
release-3.0.x
f0e0b64...

Reviewers

Django 1.8 uses a new, unified TEMPLATES setting. This change adds a definition
for that which is built up from the old broken-out settings. Once we cut over
to 1.8+ entirely we can move everything inline.

Ran unit tests on Django 1.6 and 1.8