Initial Ganglia entities (cluster, manager and monitor) with basic integration test

(_NOTE_ The test requires a pre-configured named location called 'ganglia' to run)
Moved to Sandbox
Refactor Ganglia entities to use interface and implementation pattern
Added Zabbix and DynaTrace monitoring entities and fixed copyright and packages
Further tidying of Ganglia.

- Updated implementation to latest API
- Convert Ganglia tests to Java
- Fixing dependencies and imports
- Add monitor agents to correct group
- Other minor fixes
Moved Asserts to brooklyn-test-support
Added general interfaces for monitoring entities
Adding sensors and configuration for Apache httpd entity
Remove unnecessary constructors and use existing serviceUp sensor
Tidying
Moved ApacheHttpd to brooklyn-software-webapp module
Make feeds extensible