Wien2k converter crashes

[johanjoensson]

The Wien2k converter method "convert_misc_input" reads some symmetry data from the "case.outputs" file, generated by the program "symmetry". When performing a spin-polarised calculation with spin-orbit coupling the number of symmetries might change. I the user runs "symmetry" after having initialised the spin-orbit coupling (i.e. after running "initso_lapw") there will be warnings and blank lines printed in the "case.outputso" file. The Wien2k converter assumes that there are no blank lines in "case.outputso", and crashes when it encounters one.

In the gist is a git diff showing our solution to this problem, essentially we read the symmetries in "case.struct_st", compare the number of symmetries with the number of symmetries in "case.struct" and raise an IOError if they do not match. If they match we then read the symmetries in the "case.outputs" file and discard any that are not present in the struct file. If we do not find the expected number of matching symmetries we raise an IOError.

This has been tested on the py2_compat release, the bug is present also on the 3.0.0 release.