Maintenance update
- Fix a number of bugs and improvements to resiliency.
- Added a number of requested enhancements (see commit changes).
- Added first-pass multiscale labelblk but has not passed testing yet. Standard dvid use (i.e., not syncing labelblk to labelbk instances) will not create issues.
- First-pass float32blk support. There are plans to refactor data block datatypes to allow arbitrary dimension and # bytes per voxel.
For Linux, binaries are compiled using Go 1.7. Linux compilation uses gcc-4.8.4 due to lz4 C routines.