Start implementing coroutine tracing in C tracer, will be hard :(

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An option to not run the PyTracer tests

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Refactor some C tracer code in prep for data stacks

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branch : c-coroutine
Refactor DataStack code into its own functions

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branch : c-coroutine
Finish implementation of coroutine_id_func in C tracer, but it doesn't make gevent better.

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Remove a TODO

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branch : c-coroutine
Update tests for really testing gevent with a C extension.

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branch : c-coroutine
Temporary debugging tweaks to tests

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branch : c-coroutine
Merge in the C implementation of coroutine support.