- Round the number of entries displayed in the statistics box to the closest...

- Round  the number of entries displayed in the statistics box to the closest integer value. This fixes a problem observed when 
 displaying the effective entries of a weighted histogram. 

- update release notes


git-svn-id: http://root.cern.ch/svn/root/trunk@30643 27541ba8-7e3a-0410-8455-c3a389f83636