Rework of Supervoxel Classes

Changes in octree:
    Renamed OctreePointCloudSupervoxel class to OctreePointCloudAdjacency
      This is now a general class that can be used for any point type
    Added OctreePointCloudAdjacencyContainer
      This class allows for storage of a data member in leaves, for things like segmentation
Changes in segmentation:
    Renamed Supervoxels  to SupervoxelClustering.
      Now uses OctreePointCloudAdjacency instead of OctreePointCloudSupervoxel
      Allows for providing a transform for octree calculation
      Returns a map of supervoxel objects, rather than a pointcloud of PointSuperVoxels
Changes in apps:
    Renamed voxel_superpixels tool to supervoxels to match with class update
Changes in examples:
    Changed segmentation/supervoxels to use renamed class, enhanced functionality and display to better show supervoxels