replaced queues in RPC layer with MoodyCamel's lock-free queues

[ryanhoque]

addressing issue #335 - performance optimization using https://github.com/cameron314/concurrentqueue

[AmplabJenkins]

Can one of the admins verify this patch?

[dcrankshaw]

jenkins ok to test

[AmplabJenkins]

Test FAILed.
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Test FAILed.

[Corey-Zumar]

LGTM. Will merge when tests pass

[Corey-Zumar]

jenkins test this please

[AmplabJenkins]

Test FAILed.
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Test FAILed.

[Corey-Zumar]

@dcrankshaw Can you try formatting this? Yapf on my machine isn't catching the C++ format violations referenced by Jenkins.

[AmplabJenkins]

Test FAILed.
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Test FAILed.

[dcrankshaw]

jenkins test this please

[AmplabJenkins]

Test FAILed.
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Test FAILed.

[ryanhoque]

From what I can tell, the Jenkins test failed to build a test suite called 'rpc-test' because it couldn't find something called 'scala-compiler-2.11.8.jar' - not sure how to resolve this

[AmplabJenkins]

Test PASSed.
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Test PASSed.