new function sos-answers and sos minor mode

Hi Rudolf 

yes, I saw the batch option but was too lazy to distribute the result
across the questions :)

and I really think that it is sufficient functionality to have answers
at the push of a button. I have just submitted a pull request which
includes the previous patch and also a new sos minor mode which binds
sos-answers to the key "A".

Cheers, Thomas