Corrects slf4j dependencies to 1.7.2, matching hydra-api.
Removes unused file and dependencies on ancient Hydra Core.
Added maven-duplicate-finder-plugin and fixed (almost) all stages
Merge pull request #1 from remen/laserval-slf4j-dependency-fixes

Added maven-duplicate-finder-plugin and fixed (almost) all stages
Merge pull request #205 from laserval/slf4j-dependency-fixes

Removed multiple logging implementations in stages, fixing problems with remote logging functionality.