Fixing locality issue

There was a data locality bug because I was using eval ids instead of
hostnames. The dfs blocks have host names. Fixing that.
Merge pull request #806 from Microsoft-CISL/shravan_dataloading_locality

Fixing locality issue
Updated wake and tang to 0.4
[maven-release-plugin] prepare release reef-project-0.4
[maven-release-plugin] prepare for next development iteration
Updated wake and tang dependencies to 0.5-SNAPSHOT
Removed some left-over files. They have been deleted earlier, but their licensing headers re-appeared, probably as part of a botched PR.
Trying to make it run
Merge remote-tracking branch 'origin/master' into shravan_groupcomm_interfaces