[Soc-2012-dev] Weekly progress report 2 - Bullet Integration

[Sergej Reich]

This week I mostly finished basic point cache support and deactivation
of rigid bodies.
It turned out that there are a couple of architectural issues that need
to be resolved first so I also started to change the way rigid bodies
and worlds are handled.
This means removing the ability to add multiple worlds to a scene and
bodies into multiple worlds. The way rigid body types are handled also
has to change (for more information refer to the design page).

I also fixed calculation of cylinder and cone collision shapes as well
as a couple of minor force field bugs.

Next week I plan to finish what I started this week and then do mostly
bug fixing.

The biggest problem was that I underestimated how much work the multiple
world issue would be. The change itself is fairly simple, it just
touches a lot of places.