this patch prevents all dictionaries from being rebuild when non dict related
changes are made in CINT. When the dictionaries change the new
cint/inc/cintdictversion.h must be updated which triggers a dictionary
rebuild. For example:
touch cint/src/v6_var.cxx && make: rebuild no dictionaries
touch cint/inc/cintdictversion.h && make: rebuild all dictionaries
touch utils/src/rootcint.cxx && make: rebuild all dictionaries


git-svn-id: http://root.cern.ch/svn/root/trunk@21802 27541ba8-7e3a-0410-8455-c3a389f83636