[Bf-python] small modifs proposal

[Jacques Guignot]

Hi Willian,

I think you are right. I'll contact yable's author.

For features we don't really want to put in the api, but which break a 
script, our policy should be :

    a) bad scripts :
    mv badscript /dev/null

    b) good scripts : ask the author to update it, or, better, prpose an 
update.
       b1) cool authors : they accept
       b2 ) not so cool... add the needed feature but don't document it 
(and mark as "hidden" in the source code, for future maintainers)