adds groupByN utility function for use in TM
adds groupByN utility function for use in TM

lscheinkman/nupic,numenta-ci/nupic,badlogicmanpreet/nupic,ywcui1990/nupic,arhik/nupic,arhik/nupic,blueburningcoder/nupic,numenta/nupic,rcrowder/nupic,cogmission/nupic,alfonsokim/nupic,ywcui1990/nupic,subutai/nupic,subutai/nupic,neuroidss/nupic,vitaly-krugl/nupic,marionleborgne/nupic,EricSB/nupic,marionleborgne/nupic,scottpurdy/nupic,numenta-ci/nupic,lscheinkman/nupic,scottpurdy/nupic,EricSB/nupic,arhik/nupic,rhyolight/nupic,vitaly-krugl/nupic,ywcui1990/nupic,blueburningcoder/nupic,pulinagrawal/nupic,numenta/nupic,pulinagrawal/nupic,subutai/nupic,rcrowder/nupic,lscheinkman/nupic,blueburningcoder/nupic,numenta-ci/nupic,neuroidss/nupic,vitaly-krugl/nupic,rhyolight/nupic,numenta/nupic,EricSB/nupic,rhyolight/nupic,neuroidss/nupic,rcrowder/nupic,cogmission/nupic,scottpurdy/nupic,badlogicmanpreet/nupic,alfonsokim/nupic,cogmission/nupic,marionleborgne/nupic,alfonsokim/nupic,badlogicmanpreet/nupic,pulinagrawal/nupic