Support timeouts in OAuth1Future
Summary: Ref T13291. Ref T13285. Add "setTimeout()" to OAuth1Future to support adding timeouts to Doorkeeper OAuth requests, so we're less likely to cascade into explosive failure if a linked JIRA instance dies.
Test Plan: See next change.
Reviewed By: amckinley
Differential Revision: https://secure.phabricator.com/D20529