Fix to classification problem implemented in multiclass_concat
Now safe to rerun multiclass_concat more than once
Cleaned up warning message on multiple runs of multiclass_concat
Specification of --dedup-info is now optional, with a warning message
multiclass_concat prints status through log.info
A bit of docstring and help text cleanup/additions
dedup_info is now required unless --no-dedup is specified; hopefully this is more fool proof, since it's easier to miss a warning than an error
Fixing up changelog