setup License file for repository (MIT)
add external projects (not part of the EELcalc package)

- only added for convenience, redistrubuted under their own Licence
  -> GracePlot (contains slight modifications)
  -> interspectus (original)
add input-tools for DP-files
add modules for polarizability of graphene

- from my own RPA calculations (using AbInit+DP+Cutoff)
- hydrodynamic model with parameters from literature
add scripts for AR-EELS of multilayer-graphene

- with publication P.Wachsmuth, R.Hambach, G.Benner, U.Kaiser, PRB (2014)