Issue #29: improve YAML export format. I do a regex match with

    data: 
    - int
    - int
    - int
    - int
    - int
    - int
    - int
    - int
    - int
    - int
    - int
    - int
    ...
I hope it's restrictive enough! Btw, I didn't tested with more that one
map.
Make debug=true/false argument optional