Mark charts of dead Java processes obsolete.

[simonnagl]

trafficstars

If a Java process gets killed we currently do not collect values any more, but the chart get's empty. For auto-configured processes, if the process is started with a new PID there is no chance to attach this process to the old charts.

We do not want to spam the metadata dashboard creating new charts and not removing the old ones. We want to mark charts which we won't refresh any more as obsolete.

[simonnagl]

Migrated to https://github.com/firehol/netdata/issues/2798

[simonnagl]

Emigrated from netdata/netdata#2798