Squashed commit of the following:

commit 5111e0e377afc94ad08ba2ca9ad3ec5b2cc22a93
Merge: ebd35d7 62f7e4c
Author: RashmiDR <rashmi@datatorrent.com>
Date:   Wed Jan 29 18:09:40 2014 -0800

    Merge branch 'master' of https://github.com/DataTorrent/Malhar into directoryScanInputOperator#321

commit ebd35d7e0ef9f522c8427dceff883a4e04df7a67
Author: RashmiDR <rashmi@datatorrent.com>
Date:   Wed Jan 29 18:09:03 2014 -0800

    directory scan input operator that scans the given directory and emits file info records, fixes MLHR#321