keep inactive bodies on separate lists

Keeping inactive bodies on the same double-linked list as the active bodies 
requires unnecessary iterations when stepping the world. They should be kept 
separately.

Issue 212 (apparently) contains this plus several other enhancements, but it is 
for C#.

Attached patch is a proof-of-concept implementation, but obviously it is ugly 
and I think there are some special cases missing, so do not apply. If there is 
interest I could clean it up.

This is Box2D C++ v2.2.1.

Original issue reported on code.google.com by marcus.a...@gmail.com on 7 May 2012 at 6:02

Merged into: #212

Attachments:

dormant_box2d.patch

owashe / box2d

keep inactive bodies on separate lists #282