Bug 929435 - Treat undefined as null in Contacts API strings. r=gwagner

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extra : rebase_source : a838d31f1d1f7fbff04bdebc865d2234a5e958d5
Bug 932763 - Setting mozContact's array properties to an empty array should work. r=gwagner

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extra : rebase_source : bdc09f04d31e72fafce8b8ef5726d1d0288c8efd