Unify labeling mechanism with embedded automated job-level labels

[Ilya Fomin]

Plain text labels are not a way to go if you're supporting a lot of builds with similar steps.

I suggest to support the functionality that exists in Bamboo at job level, e.g.: - Support of bamboo variables in label text (high priority) - Support regular expressions (medium-low priority for me)

The idea of supporting it in similar fashion as for job-level labels is that consistency is great, and also you can actually get source code of bamboo and copy handling of the fields directly into your code.