Adding palm accessor method that fetches left or right, as specified.
Adding simple CollisionInfo class as data wrapper and a findSphereCollision() method to AgentData API.
Adding initial Agent::findSphereCollision() implementation and removing some debug log spam.
Minor cleanup: moved #include out of header and into cpp file.
Adding methods to Model for accessing hand info and computing hand collisions.
Adding findSphereDiskPenetration() method for hand paddle experiment.
First pass at particle-hand collisions using hacked hand capsules.
Merge upsteam master into current project (experimental hand paddles)

Conflicts:
	interface/src/avatar/Avatar.cpp
	libraries/avatars/src/AvatarData.cpp
bugfix: findSphereDiskPenetration() would never return true
Changing where the "hand palms" are drawn.  Will back them up with collision proxies soon.
Adding disk collision proxy for hand paddles.
All avatars now have disk collision proxies at their hands.
merge upstream work into local repo
Moving SIXENSE_CONTROLLER_ID* constants into header to help eliminate magic numbers in other code (to be committed later).
Removing magic numbers, but still only supporting 2 hands (the SkeletonModel currently has two hands hardcoded).
Removing Model::findSpherePenetrationWithJoint() which was experimental method that was not finally used.
Uncommenting particle shift on penetration.
Merge latest upstream into local repo.
cruft removal
merge upstream with local repo