Adding notification interface implementation and test.
Implemented control interface.
improved setting of status. When Controller IFs are invoked, they are aborted when the status is not 'running'.
Added function to write a configuration instance to the ngeo config file.wq
Added facilities to read and encode configuration values with its XML schema. Parsing and writing configuration is still to come.
Added view to retrieve the current configuration and schema.
Added test case for configuration and schema retrieval.
Merge branch 'controller-IF-control-notification'
Fixing problem with status API.
Fixing status retrieval in controller server intf view.
Moving status config setup to a higher hierarchy.