Make Convergence standalone

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It would be more useful if we could run Convergence as, say, a S.O.C.K.S. proxy,
because then we could use any internet-facing program with Convergence.
For example, package managers would benefit from being able to trust the
repository servers reliably.

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Had to write S.O.C.K.S. the way I did because my ISP dislikes
anything to do with subverting the child protection filter it runs

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Duplicate of issue #160