- changed the way we calculate whether or not to render a parent "average" voxel so
that if any of it's most distant child would not be visible, then it's used instead
of it's children
- added precalculated value for topFarLeft corner of AABox (optimization)
- changed VoxelSystem::newTreeToArrays() and VoxelTree::encodeTreeBitstreamRecursion()
to use the same help function for determining this LOD boundary behavior
- deleted old dead code in voxel-server and VoxelTree for picking which node to start
sending with, since it wasn't being used
- added VoxelNode::furthestDistanceToCamera() which tells you not the distance to the
center of the voxel, but the distance from the camera to the furthest corner relative
to the camera.
- added ViewFrustum::getFurthestPointFromCamera() which given an axis-aligned box will
tell you which vertex of the box is furthest from the camera
- make octalCode and children members private
- add public getters for accessing these private members
- change constructor to require an OctalCode for all non-roots
- default constructor constructs a rootNode
- make primary access for deleting, adding, and accessing children through public methods that do bookkeeping
- calculate AABox on voxel creation so that we don't need to do all the math when we deal with voxels
- added methods on VoxelNode for common items like getCorner(), getCenter(), getLevel(), etc
