Bug 827225 - Rename JS_GetTypedArrayType to JS_GetArrayBufferViewType, add TYPE_DATAVIEW. r=bz, sr=dmandelin

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extra : rebase_source : c5947273c5d517338ea1f468358511aa979b4959
Bug 827225 - Avoid JS_GetArrayBufferViewType until safe to call. r=bz

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extra : rebase_source : 5ac40b7fc9567cc02ab2f2167f756348f1a44fd0