Bug 839746: global private windows (Fx <=19) are not ignored, per widnow private windows (on Fx > 19) still are
(cherry picked from commit ad44c4bc411d48af3cf001703729cf928fcc3ee9)
Bug 839746: added tests for tabs/utils getTabs, added tests for panel/window getWindow, and page-mods in global pb
(cherry picked from commit 529de8625b6d9d3ea6b2051c34c8291f12ef4453)

Conflicts:

	test/test-panel.js
Merge pull request #894 from erikvold/839746-4-stabilization

Bug 839746 for stabilization: global private windows are not ignored r=@gozala