minor optimization of MuscleConstraint::enforce()
Rename ContactConstraint to ContactPoint
fix bug: false positive capsuleCapsule() collision

for capsules with parallel axes and negative pojection of
center-to-center separation

also replace fabs() with fabsf()
add Shape::getVerletPoints()
ContactPoint = set of assymetric distance consraints
merge upstream/master into andrew/ragdoll
Merge pull request #3253 from AndrewMeadows/ragdoll

Ragdoll Part 8: improved contact points
remove dangling shape pointers from PhysicsSimulation
Merge pull request #3255 from AndrewMeadows/ragdoll

remove dangling shape pointers from PhysicsSimulation
Merge branch 'master' of https://github.com/highfidelity/hifi into metavoxels
Use back face culling on the heightfields.