remove unused cruft from Model class API
Model now knows its bounding radius
Adding per-palm penetration accumulator
Hands can collide with avatar head again
Merge upstream/master' into shapes branch
Merge upstream/master

Conflicts:
	interface/src/avatar/MyAvatar.cpp
degrees instead of radians for head lean deltas
Merge upstream master into "shapes" project
fixing signed/unsigned comparison
improved index sanity checking
merge upstream/master into "shapes" project

Conflicts:
	interface/src/avatar/MyAvatar.cpp
	interface/src/avatar/SkeletonModel.cpp
	interface/src/avatar/SkeletonModel.h
	libraries/avatars/src/HandData.h
	libraries/shared/src/SharedUtil.h
Merge branch 'cleanup' into 'shapes'
fix sphere-capsule collisions at the capsule caps
Adding StreamUtils for common debug output
Add penetration resolution helper for Hand class
merge upstream/master into physics project

Conflicts:
	interface/src/avatar/Hand.cpp
	interface/src/avatar/Hand.h
	interface/src/avatar/SkeletonModel.cpp
	interface/src/avatar/SkeletonModel.h
	interface/src/renderer/Model.h
Merge branch 'master' of https://github.com/highfidelity/hifi
avatar responds to hand-vs-head collisions again
reduce the lean recovery timescale
remove cruft: Head::applyCollision()