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.
I really don't like creating arbitrary new util class. We already have too many. Since it is very specific to Command implementation for command parsing, maybe it's better to have an `AbstractCommand` class that host this type of methods.

Also, as a side note, we should go for naming convention that use 's' suffix instead of 'Util' suffix for helper class.