Add enum for commit status in Stash
Extract vote method
Add a build problem when request to Stash failed
Add comment escaping
Report build comments to Stash
Report build is interrupted to Stash
Notify Stash when build started to fail
Use buildId as key

This allows to have several messages from single build configuration
Calculate a build revision for publishers
Publish build queued/build removed from queue events to Stash

Switch to build promotion id as a key for a vote since queued build
doesn't have its own id.
Use buildType external id as a key

Stash marks a pull-request as failed when at least one build is
failed, it's more convenient to have a status of the last build.