Modification to xfm.py to avoid string/unicode error
Modification to xfm.py to avoid string/unicode error

smerdis/pycortex,CVML/pycortex,gallantlab/pycortex,gallantlab/pycortex,smerdis/pycortex,gallantlab/pycortex,gallantlab/pycortex,CVML/pycortex,CVML/pycortex,smerdis/pycortex,smerdis/pycortex,gallantlab/pycortex,smerdis/pycortex,CVML/pycortex,CVML/pycortex