[Bf-python] Final Ipo/IpoCurve API revisit

[Ken Hughes]

Ken Hughes wrote:
> Gilbert, Joseph T. wrote:
> 
>> """ per-Ipo attribute which provides a dict or list of just the 
>> constants for that Ipo type"""
>> I like this idea but with constants. Remember that if your returning
>> constants loaded into the module dictionary and return some subset of
>> this to the user you're simply passing him a reference to objects that
>> already exist in the module's dictionary rather than creating a ton a
>> strings to return to the user.
> 
> I was thinking that this dict/list would instead of the module 
> constants, not in addition to them.  I guess this would be a 
> "convenience" attribute to let the user know which of the values are 
> valid for that Ipo type.  Good idea.

I'll update the wiki with this info also, but thought I'd poke 
interested parties here (link follows):

http://mediawiki.blender.org/index.php/BlenderDev/Ipo#Ipo_attribute_for_determining_valid_curves_.28per-Ipo_specific.29

I've run into some issues of practicality and efficiency implementing a 
per-Ipo list/dict of curve constants.  It could be that I don't 
understand a better way to do efficiently.  Hints and tips welcome.

Ken