adding RagDoll scaffold
merge upstream/master into andrew/ragdoll
Merge pull request #2988 from AndrewMeadows/ragdoll

RagDoll Part 1: basic data structure
fix for broken windows build with PrioVR libs

The Model API changed but this code path was not updated.
both left and right hands in animation
Merge pull request #2990 from AndrewMeadows/bug-fix

fix for broken windows build with PrioVR libs
Temporarily disable enum streamers, which are crashing on Windows startup.
Merge pull request #2991 from ey6es/master

Temporarily disable enum streamers, which are crashing on Windows startu...
Merge pull request #2992 from PhilipRosedale/master

Left and Right hands have clasping animations in squeezeHands.js
Merge branch 'master' of https://github.com/highfidelity/hifi into metavoxels
Reenable enum streamers here.