Allow map-reduce result mappers to return non-deferreds by using maybeDeferred.
Allow map-reduce result mappers to return non-deferreds by using maybeDeferred.

harrissoerja/vumi,TouK/vumi,harrissoerja/vumi,harrissoerja/vumi,vishwaprakashmishra/xmatrix,vishwaprakashmishra/xmatrix,vishwaprakashmishra/xmatrix,TouK/vumi,TouK/vumi