Bug 809920 - Create testing/modules for shared testing-only JS modules; r=ted

Includes AppInfo.jsm with code for manipulating XULAppInfo.

--HG--
rename : services/healthreport/modules-testing/utils.jsm => testing/modules/AppInfo.jsm
Bug 835767: AsyncConnectionHelper::ConvertCloneReadInfosToArray callers don't need to clear structured clone buffers. r=bent