Change object construction to prevent Chrome v32 crashing.

We were getting reports that our website was crashing in Chrome. We were able to pinpoint it to moment.

Changing the config from a literal object to setting properties is ugly, but resolves the issue for us in production. Given how frequently Chrome is updated I suspect we'll be able to revert it once it's fixed upstream.

See https://github.com/moment/moment/issues/1423.