include GMTKN30 data

[marcindulak]

Consider pulling the http://www.thch.uni-bonn.de/tc/downloads/GMTKN/GMTKN30/GMTKN30main.html data available in https://wiki.fysik.dtu.dk/ase/.
Basic functionality is illustrated below, feel free to convert it the way you want:.

cd /tmp
svn co https://svn.fysik.dtu.dk/projects/ase/trunk ase
cd ase
cd ase/data
PYTHONPATH=../../:$PYTHONPATH PATH=../../tools:$PATH python gmtkn30.py
cd -
cat <<'END'> gmtkn30_test.py
from ase.data.gmtkn30_g2rc import data
from ase.data.gmtkn30_g2rc import info
from ase.structure import molecule
from ase.calculators.emt import EMT

# reaction number N in the g2rc set
N = 1
energy = 0.0
for compound, stoichiometry in info['reactions'][N][:-1]:
    e = molecule(compound, data=data, calculator=EMT()).get_potential_energy()
    energy = energy + e * stoichiometry
print energy, info['reaction energy']['reference'][N]
END
PYTHONPATH=.:$PYTHONPATH PATH=tools:$PATH python gmtkn30_test.py