reworked pipeline to suit all branches

This pulls, builds and publishes now for every branch on the repo
Tag used is the branch name

if the commit the pipeline runs matches the format [0-9]+.[0-9]+.[0-9]+
the release stage is run additionally, which pushs the built image
additionally with the tags 'latest' and the tag.

On Jenkins the old Pipeline configurations are disabled and replaced by
a multibranch pipeline configuration