In a nutshell, we added a more reliable check, based on if the origin is in the GJK simplex, to determine if we are really intersecting and need to run EPA.
See also "Real-time Collision Detection with Implicit Objects" by Leif Olvang
Todo: integrate the simplex penetration check directly inside the Bullet btVoronoiSimplexSolver
and remove this temporary code from libCCD
Note, for large differences in shapes, use double precision build!