due to technical limitations this requires to wire the adaptor
as replacement for the subject Activity, so that it can capture
and log the activation, and then pass it on to its watched subject
...turns out that util::toString does not explicitly handle pointers differently,
for very good reasons; this function must always work, always produce a simple and
compact representation, and it must be possible to instantiate the template
and take a function reference (which precludes adding an overload for pointers)
