Updated node header reading to support partial Gunzipping in node > 5.0.0
Updated node header reading to support partial Gunzipping in node > 5.0.0

nellh/bids-validator,chrisfilo/bids-validator,Squishymedia/BIDS-Validator,suyashdb/bids-validator,nellh/bids-validator,Squishymedia/bids-validator,nellh/bids-validator