prepping for Hadoop-2: don't prepend hard-coded default root to the path.
  let Hadoop take care of it.
  fix ArrayIndexOutOfBound exception after no-arg usage message.
  clean up code format, make help message look nicer.
  (does not fix: -d is supposed optional, but 1st arg is required))
Merge pull request #3 from internetarchive/hadoop2-prep

don't prepend hard-coded default root to the path...