Bug 933497: Teach ObjectWrapper.jsm to deal with Typed Arrays. r=bholley

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extra : rebase_source : ed6d5f41e302e7e0d721f533c9cdb773b381fc4f
Bug 934563: Use the safe JSContext since it will always exist. r=bholley

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extra : rebase_source : 828e6c0c3f9bbc689a791839545cb403a0d2e03d