Add watch button to instance overview (fixes #655)
Add watch button to instance overview (fixes #655)

Note that watching an instance results in quite a few notifications
being generated.

alkadis/vcv,phihag/adhocracy,phihag/adhocracy,phihag/adhocracy,DanielNeugebauer/adhocracy,alkadis/vcv,liqd/adhocracy,liqd/adhocracy,phihag/adhocracy,phihag/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,DanielNeugebauer/adhocracy,liqd/adhocracy,alkadis/vcv,DanielNeugebauer/adhocracy,alkadis/vcv,liqd/adhocracy,alkadis/vcv