Improve yarn container command

While running yarn container -list <Application Attempt ID> command, some observations:

1) the scheme (e.g. http/https ) before LOG-URL is missing
2) the start-time is printed as milli seconds (e.g. 1405540544844). Better to print as time format.
3) finish-time is 0 if container is not yet finished. May be "N/A"
4) May have an option to run as yarn container -list <appId> OR yarn application -list-containers <appId> also.
As attempt Id is not shown on console, this is easier for user to just copy the appId and run it, may also be useful for container-preserving AM restart.