First cut at new Voxel Sending strategy

- added "--newVoxelDistributor" command line option
- fixed crashing bug for derefrencing NULL pointer in case where server is started which interface agents already in the domain. Basically agentData may not yet be setup properly
- fixed bug in createMissingNode() where we would accidentally stomp on a previously created peer tree while creating a new node
- improved printTreeForDebugging() to include more details
- fixed a bug in readBitstreamToTree() for multi-tree case where we weren't correctly walking through the buffer
- added VoxelNodeBag member to keep track of which nodes this agent needs to have sent to it
- changes to VoxelAgentData to support new voxel sending strategy 
- added encodeTreeBitstream() which is new version of bitstream encoder that handles only encoding nodes that are in view. Also handles detecting packet overflow with new technique
- new methods in VoxelNode class for things like isLeaf(), isInView(), etc.
- new helper functions for comparing octalCodes for depth and matching