Summary:
Required in order to run tests successfully in the HipHop interpreter.
Similar to D2362.
Test Plan: Run the tests in an HipHop runtime.
Reviewers: epriestley
Reviewed By: epriestley
CC: jungejason, aran, Koolvin, vrana
Differential Revision: https://secure.phabricator.com/D2365
Summary: Introduces a scope-guarded way to override the env config, for unit tests which are sensitive to config values.
Test Plan: Ran unit tests.
Reviewers: btrahan, vrana, jungejason
Reviewed By: btrahan
CC: aran
Differential Revision: https://secure.phabricator.com/D2237
