From Lorenzo:

patch to fix TGraphAsymmErrors::BayesDivide (bug https://savannah.cern.ch/bugs/?30246).
 Fixed by increasing precision when inverting the integral of the beta (beta quantile). In the long term should be fixed by using directly ROOT::Math::beta_quantile


git-svn-id: http://root.cern.ch/svn/root/trunk@20387 27541ba8-7e3a-0410-8455-c3a389f83636