a note on commit messages

[Ferdinando M. Ametrano-2]

Hi all

I've just posted a summary of recent development to quantlib-users
If I summarized your work incorrectly, please fix the description in the
file News.txt of QuantLib, QuantLib-Python, and QuantLib-Ruby.

Even better: please write extended commit messages when committing to the CVS.

ciao -- Nando