Backblaze Client Update

This update contains solely a recompile with a newer upstream github.com/kothar/go-backblaze library. This fixes the snapshot bucket issue.

Progress has been made

Changes since v0.1:

• SHA1 checksum is calculated in parallel with the initial request to B2 during uploads; somewhat better upload latency.
• Progress reports during file uploads and downloads

Initial release

v0.1

make-dist: added