update to use brooklyn M2
- updated to point at brooklyn 0.5.0-M2 (from 0.5.0-M1)
- Use interface+impl for each entity
- Use ApplicationBuilder
Bump local version to 0.2.0-SNAPSHOT from 0.1.0-SNAPSHOT

- This is major non-backwards-compatible changes, so perhaps worth
  having a 0.1.x branch available.
  Have not created that yet though.
Merge pull request #5 from aledsage/upgrade/brooklyn-m2-prep-strike2

update to use brooklyn M2 (prep)