Automated method to extract file from DataPackage / DataObject

[gothub]

There is no automated way to extract data from a DataObject into the correct file
format (binary vs text) with the proper file type. One current method is to use
getMember() to extract a DataObject from a DataPackage, then use getData() to extract
the data from the DataObject, then use rawToChar() if necessary with something likewriteLines
or some similar function to write out to disk. All this should be incorporated into a single
function.