Seeing voxels & particles in JS

* clean up a bunch of cruft
* added OctreeHeadlessViewer class that does most of the work of acting like a client viewer and allowing implementations to query voxels or particles and maintain a local copy
* removed some Voxel stuff that is replaced by Octree stuff
* got rid of old menu options for managing octree protocol features - now you get the default and change it - closes #2109
* fixed a bug in jurisidiction listener introduce when we switched to PacketType enum