JSAGA

job.state_detail must fire only when value has changed, according to page 187 of the SAGA specification.

This regression appeared when the JSAGA state model has been added to the job.state_detail metric (in addition to the middleware state model). Indeed, from the metric point-of-view, the value is always considered as changed since it is always switched between the 2 models.

• remove support for the middleware state model (this is prefered alternative).
• remove support for the JSAGA state model.
• Override the MetricImpl.setValue() method in order to keep the previous value of both models simultaneouly.