This is something I wanted to clean-up since a very long time indeed,
but always postponed it, since it requires a lot of nasty clean-up and disentangling....
Several parts had been stashed away into `src/lib/test`, which are not really related:
* the testrunner and testsuite builder
* generic helper utilities
* specialised test-support facilities, e.g. the EventLog
This changeset introduces a new top-level test folder and a namespace `::test`
Code from this folder is linked into a shared library `libtestsupport.so`,
which resides in the linkage hierarchy between »Vessel« and »Vault«,
yet is no longer part of the Lumiera application and only linked into the test-suite.
Building a correct processing-identification is a complex and challenging task; only some aspects can be targeted and implemented right now, as part of the »Playback Vertical Slice«
* components of the ProcID
* parsing the argument-spec
* dispatch of detail information function to retrieve source ports
The choice to rely on strictly typed functor bindings for the Node operation
bears the danger to produce ''template bloat'' — it would be dangerous to add
further functions to the Port-API naïvely; espeically simple information functions
will likely not depend on the full type information.
A remedy to explore would be to exploit properties marked into the Port's `ProcID`
as key for a dispatcher hashtable; assuming that the `NodeBuilder` will be responsible
for registering the corresponding implementation functions, such a solution could even
be somewhat type-safe, as long as the semantics of the ProcID are maintained correctly.
