merge from trunk improvements in TAxis::SetRange (r 46234 and 46244)
(see  https://savannah.cern.ch/task/?19000 and https://savannah.cern.ch/bugs/?97331 )


git-svn-id: https://root.cern.ch/svn/root/branches/v5-34-00-patches@48225 27541ba8-7e3a-0410-8455-c3a389f83636