"Sensor feed" for java (to replace sensor adapter)

Feedback on this large body of code would be most welcome!

The new "feeds" are intended to replace the old sensor-adapter and sensor-registry classes; they are more java-friendly rather than being groovy.

See discussion on brooklyn-dev with title "Sensor-adapters for entity-authors: java API" [1].

Includes:
- HTTP Feed
- JMX Feed
- SSH Feed
- Shell Feed (i.e. does runtime.exec)
- Function Feed
- Converts Jboss7 and Jboss6 entities to use http and jmx feeds respectively 
- Deprecates old sensor-adapter classes

Remaining work:
- in javadoc of each feed, give example code (e.g. pick a nice example from integration tests)
- think about what to do with ConfigSensorAdapter (e.g. just extract static ConfigSensorAdapter.apply)
- update docs

[1] https://groups.google.com/forum/?fromgroups=#!topic/brooklyn-dev/5Cz7dR300wY