Add outer param to TPC-ITS match (not functional yet)

DPL: Use DataDescriptorMatcher on incoming data

This changes the DataRelayer so that we use a DataDescriptorMatcher,
rather than the InputSpec to match incoming data. At the moment
the matcher is derived from the InputSpec hardcoded values.

DPL: mitigate impact of Monitoring::send.

Readme and cleanup of data sampling

Readme and cleanup of data sampling

Readme and cleanup of data sampling

DPL: prevent InputSpec default constructor

As we move closer to have InputSpec as a veritable "matcher" object
rather than a set of variables to be equal compared, I need to tight
the access to the member variables. The first adiabatic step in such a
direction is to make sure an InputSpec is built all at once, and not
incrementally, as that ability will be lost once we move to use
a DataDescriptorMatcher to describe the InputSpec internal State.

DPL: allow saving all dangling outputs to a file

Ability to actually select what to save (and drop everything by default)
being worked on.

DPL: allow saving all dangling outputs to a file

Ability to actually select what to save (and drop everything by default)
being worked on.

Fix forwarding inputs to consumers which are time-pipelined