[Bf-python] Another stab at scheduling Ipo/Curve integration

[Ken Hughes]

This is mainly for stivs, IanWill or ascotan, since your names
are on the list as Module Owners :-)

I'd like to get pre-approval, blessing, whatever on a course
of action on the Ipo/Curve integration: at least enough to
know that once I upload a patch for approval, I can work on
the next part (or parts) without worrying that the intent
of the patch (not the implementation) is totally wrong.
My goal is avoid need to keep 6 different versions of
the modules below (for each state) in my source tree if
possible.

So here's the stages; some of this is already done or
in partially implemented:

   (1) implement a rudementary BPoint module, enough to
       wrap Blender data (done)
   (2) implement sequence operators on BezTriples and
       BPoints, plus append/insert/delete/iterators
       (done)
   (3) integrate sequence operators into IpoCurve and
       CurNurb modules (testing)
   (4) implement dictionary constants for Ipos; this
       presents valid curve names, through module constants,
       which are used to get/append curves to Ipos
       (partially implemented)
   (5) mark for deprecation methods in IpoCurve, CurNurb,
       Ipo and Curve which are superceded by the new code
       (to do)
   (6) adding more methods to BPoint, BezTriple as needed
       (partially implemented)

After this, implementing tp_getset tables for IpoCurves
and CurNurbs would be next, but stivs is already working
on this so I'm waiting to see how that works.

If you want to see code examples for any or all of these,
I'll be glad to put them up on the wiki.

Ken