testbench: make more reliable shutdown

so far, we checked only the main queue size to become zero, ignoring
the sizes of action queues. For some tests, this caused racieness and
unreliability. Now, we check all queues. This should make matters
much more stable.
regression fix: invalid ptr was passed

happend by merging patches this morning, never released
Merge branch 'v7-stable' into v8-stable
fix: remove accidently left-in debug output (in previous commit)
testbench: add -m option to chkseq

This permits to check files with a limited number of missing messages
testbench: adjust test to new config param defaults

The test didn't make sense with the new defaults, as the disk queue
was never activated. While at it, also improved test output a bit.
Merge branch 'v8-stable' of git+ssh://git.adiscon.com/git/rsyslog into v8-stable
Merge branch 'v8-stable'