[server] add a looping task to free unused cnxsets capture by dead pyro When a pyro client disconnects, we're not necessarily notified so they can hang on to their session/cnxset forever. Don't let them do that. The hacky looping task is only installed when pyro is enabled. This optional activation save this very hacky patch from being rejected. closes #2825380

Schema of the data
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First take a look at the data schema_ then try to remember that you are browsing
through a heap of data by applying stylesheets to the results of queries. This
site is not a content management system with items placed in folders. It is an
interface to a database which applies a view to retreived data.

.. _schema: schema