Improvements

Bug Fixes

Fix bosh-dns-healthcheck feature - thanks @michaelmccaskill (#126)
Better support for params.dns when specifying a single entry - thanks
@michaelmccaskill (#122)
Recent changes in the bosh-cli broke the login addon. Empty environment variables is treated as a value.
Fixes for rutime addon:
1. Use overlay style for including os-conf release because it gets concated
  into an existing overlay style file, which was incompatible with its
  previous operator style.
2. Improve runtime-config interface, to give better feedback for runtime
  uploads.
3. Delete genesis.ops-access runtime if both netop-access and sysop-access
  features are not present (instead of uploading an empty runtime config)
4. Fix exclude of genesis-local-users runtime job (it was in the wrong
  level, and therefore uneffective.