fix small typo
give more descriptive name to object that is passed to FileMakerXMLMaker
actually display both input and output, as promised

pass hash instead of string to FileMakerXMLMaker
hash has two key value pairs, one for the input (my_string)
and one for the output (rot13 version of my_string)
add iterator in FileMakerXMLMaker#to_fmpxml to go over each
key value pair and output it in the XML