Start updating to use rect-mip-map
Move texture2d creation to voxel-stitch
Create mesh in updateTexture(), when voxelSideTextureIDs is available

Would have liked to create the mesh before setting the texture so the
general terrain outline shows untextured before the textures load later,
but voxel-stitch now calculates updateTextureSideIDs() after 'addedAll',
and emits 'updateTexture'. The voxelSideTextureIDs array is only
populated after the atlaspack textures are added, since the texture
sizes cannot be known until then, and only then can the UVs -> indexes be
calculated for ao-mesher.
Working voxel-stitch with rect-tile-map
Fix high block test wool cloned texture, need to set after voxelSideTextureIDs is populated
Update to voxel-stitch ^0.3.0, atlaspack + rect-tile-map > gl-tile-map + mip-tile-map
Lava is transparent, too