- DEAD_PORT now uses unassigned IANA port unlike to be used on the system
(dynamic port querying is racy and we had at least once an issue, so we
can remove ambiguity here easily)
- replace some diag.sh commands by bash functions
changes some of the test commands to use bash functions
includes some small bug fixes to tests where bugs were
previously not seen due to different plumbing.
Also a couple of changes to testbench worth mentioning:
* use cp -f to ensure files can be overwirtten in VBUILD
* fix issue of missing include test file in EXTRA_DIST
* new supressions
* testbench: try to use local system dependency cache
avoid going to Internet repos if not absolutely necessary. For
development containers, they should be pre-populated with the
important dependencies.
* do not enable libfaketime if ASAN is selected
unfortunately, libfaketime does not work in that case
see also https://github.com/rsyslog/rsyslog/issues/174
