v0.1.8

This is a QA version to test new features:

1. -v flag to read version
2. parallel read from disk to further improve the performance of backup-push
3. better retries for all S3 calls
4. installation of user data into JSON sentinel to connect back up with external entities
5. numerous refactorings and code improvements

Also, I have reports from @CyberDem0n about inefficiencies of delta backups. I cannot reproduce this reports though.

If you are looking for the stable version, please use 0.1.7.