[ODE] ODE 1.0 gyroscopic terms

[Morgan McGuire]

There was recently a post that pointed out many people disable the gyroscopic
terms from their own ODE builds to increase stability.  I know that I do this
in my own build with a macro in config.h.  

Perhaps this is a good candidate for the 0.6 and 1.0 release...either as a
config option or a runtime switch.  Anything that is conventional wisdom
exploited by many users should probably be an option for all (especially new)
users.

-m