correct sign

Change the sequence of parameters for consistency.

Conversion of parameters from old drude term to new drude termwp_new = wp_old / sqrt(epsinf)
γ_new = λ_old * wp_old

- get number of periodic layers
- calculate size of xout and yout

1 to 1 correspondence of formulas to literature.

boson part to be done.

to be tested

- do not multiply with ε∞ (Lambin version of ωp)
- correct the index for more than one layer
- extended Drude not tested yet.