Implement functional tests that demonstrate each degradation component

[witherspore]

These should use the functional testing support classes set up in issue #6 to test the proxy server end-to-end with another embedded real server.

There should be at least four tests to cover Delay, Discard, SlowDown, and PeerClose. These should also verify the ScenarioSelector behaviors and metrics.

While driven by JUnit, these are not unit tests

[adonciu]

Implemented the following functional tests to demonstrate end-to-end slow-light proxy server having various configurations like - delay, random data, discard, etc.

com.tacitknowledge.slowlight.proxyserver.systest.DelayProxyServerIT
com.tacitknowledge.slowlight.proxyserver.systest.DiscardProxyServerIT
com.tacitknowledge.slowlight.proxyserver.systest.CloseConnectionProxyServerIT
com.tacitknowledge.slowlight.proxyserver.systest.RandomDataProxyServerIT