RCA framework initial

1.framework major components included
2.major components interface definitions
3.correlator module implemented
4.detector module initial design implemented(using bitmap to get a time period and ema to get the exact point)
oops my bad. I thought Naarad has a gist/wiki that was available externally. In that case, it would be good to do a quick summary of how shift and coefficient work together for correlation in the code doc.