Updating mayavi changes file

Hi,

Over the last several weeks many of you have made checkins into mayavi. 
  I would really appreciate it if you please go over your checkins and 
summarize the most important of them in the docs/mayavi/CHANGES.txt in a 
manner similar to what Gael and I have done.  There is one change that 
Judah made that I have summarized (the adder node) but apart from that I 
haven't added information on any of the other major changes.  I think 
I've covered all my major changes so far.

Thanks!

cheers,
prabhu