Fix for bug 839529 (Remove various CC participants that don't do anything). r=smaug.

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extra : rebase_source : 8a272905c79396e7ae08aaaf83566ac450c45be0
Fix for bug 830342 (Scale combobox is broken in print-preview, after selecting "Custom" and then hitting "Cancel" on its spawned dialog). r=dolske.

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extra : rebase_source : 6c8804f960ac42e0773d4283637bf4073aeb408c