CDAP-633 RunId of Currently Running Program 

Based on the discussion at
https://issues.cask.co/browse/CDAP-633

history endpoint is moved to /runs endpoint, with default call to runs will return all currently active and past runs of a program.

while /runs?status={completed/failed/active} can be used to filter the returned records.

This PR contains CLI command change and UI changes as well.
setStart is called when program is started, and setStop is called from the listener for stop in the controller.