Bug 913967: port Bug 912856 to comm-central to fix bustage, r=Standard8, a=bustage-fix.

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extra : rebase_source : c8fc0d642df7ee7891ee498c78e3f6c79d2de503
Port MOZ_FOLD_LIBS=1 to comm-central to un-bust Windows builds, no bug, r=Standard8, a=bustage fix for CLOSED TREE.

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extra : rebase_source : 2ba9ea93ec39329d042ce478bbe662bee09c8a70