New Entities Features

Adds...
* Stretchability, true Dimensions
* Angular Velocity
* Visibility
* registration point - now you can rotate or place entities based on an location within the entity space, this allows for easier editing and rotating
* natural dimensions
* new UI for "natural dimensions"
* fixes the crash in butterflies.js

this change fixes the crash in the butterflies.js script by moving the LOCAL tree edits to before the SERVER edits. This works around a potential race condition of trying to update the local tree while the server is sending changed data to the viewer.