Bug 817477 - Remove support for global private browsing mode; r=jdm,glandium

--HG--
rename : browser/app/profile/extensions/testpilot@labs.mozilla.com/modules/setup.js.in => browser/app/profile/extensions/testpilot@labs.mozilla.com/modules/setup.js
rename : browser/app/profile/extensions/testpilot@labs.mozilla.com/modules/tasks.js.in => browser/app/profile/extensions/testpilot@labs.mozilla.com/modules/tasks.js
Merge the removal of global private browsing support