More loose typecheck for iterable in _emit
More loose typecheck for iterable in _emit

It doesn't have to be `list`, `tuple` or `GeneratorType`, it can be any iterable
that's not a string or a dict.

CyberTailor/iBlock,bzamecnik/xmltodict,solvebio/xmltodict,pombredanne/xmltodict,martinblech/xmltodict,pombredanne/xmltodict,butson/xmltodict,CyberTailor/iBlock,ahlusar1989/xmltodict,lucius-feng/xmltodict,martinblech/xmltodict,haiyangd/xmltodict,sporgj/xmltodict