Change ZAIMass object in order to read $CLASS_PATH/source/data/Mass.dat and...

Change ZAIMass object in order to read $CLASS_PATH/source/data/Mass.dat and fill the fZAIMass map rather than set by hand each mass.




git-svn-id: svn+ssh://svn.in2p3.fr/class@249 0e7d625b-0364-4367-a6be-d5be4a48d228