Delete deprecated code

- Code deprecated in 0.4
- Deprecate groovy code in brooklyn.entity.adapter, which requires
  updating some entities to use the new feeds
- Convert some code from groovy to java, to make testing/fixing easier
Fix JmxFeed blocking on start when connection fails

- Previously start() could block for 120 seconds if JMX end-point
  was down; not good for rebind in particular.
- Now JmxFeed does the connect() asynchronously
Fix failing JmxFeedTest regression
Merge pull request #740 from aledsage/delete/deprecated-code

Delete deprecated code