GRR v1.9.0: Private Registry Reporting For Duty

• Verified with grootfs-release v0.20.0

Resolves a problem where after multiple invocations of Attach some output would be lost. Also fixes private image support for various non-docker docker registries.

Major Fixes:

• Fixes calls to the docker /v2 endpoints, this was previously breaking support for private images in various registries ECR (AWS EC2 Container Registry), GCR (Google Container Registry) and JFrog Artifactory.
• Multiple invocations of Attach no longer lose output (#144412999 )

Minor Fixes:

• http_proxy property is now properly escaped (#147667115)
• Less noisy logging on start (#146489225)

Changed Bosh Properties:

• The http_proxy property is now properly escaped before being used (#147667115)
• The garden_windows job now exposes various new flags (we will start listing these when Windows is officially supported).