Bug 1052491 - Simplify IdToTypeId and add support for symbol-keyed properties. r=bhackett.

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extra : rebase_source : ee5bfd8e415aa9570e773662889d815c91636f57
Bug 1065180, part 1 - Add os.getenv() function to JS shell. r=sfink.

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extra : rebase_source : 7f1ef80db80d6ad8626f76f8338c1946868534c8
Bug 1065180, part 2 - Switch existing code from the environment object to the new os.getenv() function. r=sfink.

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extra : rebase_source : 650884862d5f6c9aef2505c0886e7a30e2eb2c6a
Bug 1065180, part 3 - Remove the environment object from the JS shell. r=sfink.

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extra : rebase_source : 9536deac7f2799cd2766f7fa1f529f9b079ed3e3