GeneratorExit should derive from BaseException, not Exception

[Terry Reedy]

| I've actually read the background on the exception hierarchy (and agree
| with it all), especially other suggestions that GeneratorExit derive
| from BaseException.  As I understand it, Guido's objections are 
threefold:

[snip]

After waiting a day or so to see if you get any more feedback here, I think 
you are ready to take your chances on pydev.  The filter object idea from 
your other post is an interesting idea for a more general solution but I 
have no opinion on practicality or acceptibility.

tjr