make main ragdoll and entity special

also addded some logic (unused) to add ragdolls of other avatars
Started on heightfield brush tool, added simple query for heightfield height
(accessible from scripts).
Working on ray intersection testing.
Fixing bug with visage find_library
Merge pull request #3260 from murillodigital/master

Fixing bug with visage find_library
namechange _frame --> _frameCount
MyAvatar's ragdoll is the main simulation ragdoll
Merge branch 'master' of https://github.com/highfidelity/hifi into metavoxels
ragdoll simulation now in model-relative frame

(same rotation as world-frame, but translated to MyAvatar origin)
add other ragdolls to simulation
VerletPoint::_mass is now private

We set the mass of other avatars artificially high
so they are less movable.
merge upstream/master into andrew/ragdoll
Working on ray intersection testing.
remove animation server
remove animation server
Divided when I should have multiplied.
small change to force rebuild
Merge pull request #3262 from ZappoMan/master

remove animation server
remove extraneous roots from Model::_jointStates
Show heightfield cursor.