Add mfee, vca etc
There is some old functionality to be added again.
Why is this feature needed?
Everyone is waiting to be able to do virtual crystal approx with b-field and e-field and...
Check old input-files...
We should include:
- apwefl file for electric fields (done incl. documentation, no testcase)
- mfee file (done incl. documentation, no testcase)
- vca.in file (done incl. documentation)
- n_mmp_rot file
- orbcomp and orbcomprot files (...)