Make use of gravatars configurable.

Review Request #5656 — Created March 25, 2014 and submitted — Latest diff uploaded

Information

Review Board
release-2.0.x
accc404...

Reviewers

When external internet access is blocked, using Review Board is annoying
because it tries to load gravatars, which can spin for a long time on every
page load, and show broken images. This change adds a setting for whether
gravatars should be used.

Looked at the page header, user infobox, and user page sidebar, and saw that
they all no longer contained broken images.