Start of work on mesh voxelization
Data to Octree Conversion

The conversion from voxel_data to voxel_octree should now work, making
sure that future voxel_data structures can also be converted to
voxel_octree
Various style changes
Merge branch 'origin_develop' into develop

Conflicts:
	include/data/voxel_array.h
	include/data/voxel_octree.h
	src/data/voxel_array.cpp
	src/data/voxel_octree.cpp
	src/main.cpp
Various changes and fixes from merge