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

Still linker errors.

tested and works.

clean and reorder

the usage of neps for the size of osc is wrong and gives a range check error.

also refactor implicit function zero in surlos.

remove common / mulayr / by
- replacing the calculation of epsmac by call of function epsilon
- move calculation of argmin and argmax to the function surlos. They are used there only.

Also add a version