Verify comment is not None when checking its length
Merge pull request #988 from TalLinzen/evoked_none_comment

Evoked: Verify comment is not None when checking its length
Merge pull request #992 from dengemann/fix_epxlained_variance

BUG: fix explained variance
ENH/API/MAIN radically improve sensor-topo API
py3k fix
cosmits
ENH: address discussion
fix PEP