Fix rhq-28: Addtional configuration elements

- storage-adapter
- server-monitor
- diagnostics

In addition to that:

- updated readme
- improve service lifecycle


Do you think it would make more sense to say `interval="60s"` or `interval="1m"` with some predefined units. Or alternatively `interval="1:23:34"` to say 1h, 23min and 45sec ?