add job execution time counter
compute the read, compression and decoding time for each file and print it to the task syslogs
update the counter value in tests
fix review comments
not considering the creation of job and input listing as part of distcp job time
refactor code in FileUtil#gzip
Merge pull request #104 from rajubairishetti/Add-logs-CopyMapper

Add a new metric to know job execution time and add logs around compression logic in the map task