Use Model methods that do the mapping between state names and indices rather than the raw Y vector to get states for visualization in GUI. Fixes issue reported by Matt on hopper model with FreeJoint that simulates correctly but displays incorrectly.
Use Model methods that do the mapping between state names and indices rather than the raw Y vector to get states for visualization in GUI. Fixes issue reported by Matt on hopper model with FreeJoint that simulates correctly but displays incorrectly.

git-svn-id: 9e047e1e624cce0a2485e750063112e834f85522@7509 fc29be9c-2cb0-420d-b520-73dbd18add6e

opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core,opensim-org/opensim-core