From Bertrand:

Added new TGMsgBox options/buttons :
- "Yes to All"
- "No to All"
- "Newer Only"
- "Append"
Modified test/guitest.C and tutorials/guitest.cxx accordingly


git-svn-id: http://root.cern.ch/svn/root/trunk@15635 27541ba8-7e3a-0410-8455-c3a389f83636