I have modified h2root to put integers of <=16 bit into shorts
for cwn ntuples. hntvar2.f needed one more argument for that.

Test on my data ntuple gave me 10% savings in disk space and therefore on
speed also since I need to do less I/O now.
use new option [optcwn] to turn on savings.

class THbookFile modified to be consistent with the additional argument in hntvar2.


git-svn-id: http://root.cern.ch/svn/root/trunk@8271 27541ba8-7e3a-0410-8455-c3a389f83636