Now supports hadoop streaming. Makes a backup of output rather than just dying when it exists. Added flags for starting and cleaning hadoop before executing mapreduce jobs.
Now supports hadoop streaming. Makes a backup of output rather than just dying when it exists. Added flags for starting and cleaning hadoop before executing mapreduce jobs.


Former-commit-id: 8fdc00866e1fb2bd693238b84988a9ea33bf90b7
manthanhd/gravity,manthanhd/gravity,manthanhd/gravity,manthanhd/gravity,manthanhd/gravity,manthanhd/gravity,manthanhd/gravity,manthanhd/gravity,manthanhd/gravity