bug 1050598 - fix proxy_over_tls pref r=hurley

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extra : rebase_source : 33517c42a9966930fd68912bf1c7a7b6fb4c2bb7
bug 1050598 - changing the pac uri should be synchronous r=hurley

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extra : rebase_source : 15cbe1d0b6c0aa966d217d7a3c64f2295eedb923
bug 1050598 - thread local jit context for pac instead of global r=hurley

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extra : rebase_source : a6f94aec59fdfafef5edc7770f7941a6a55c1923
bug 1050598 - test for proxy_over_tls pref and https proxying r=hurley

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extra : rebase_source : 27e7e50586e4a9778299912ce45858b0df873bbd