Also now permit interactivly running tests without explicitly setting
$srcdir. This now works if we are inside ./tests and fails, as before,
when we are in a different directory.
Detected by shellcheck via CodeFactor.io
Fetching journal cursor in persistJournal could cause us to save
invalid cursor leading to duplicating messages further on, when new
WorkAroundJournalBug option is set we are saving it on each
readJournal() where we now that the state is good.
pollJournal() is now cleaner and faster, correctly handles INVALIDATE
status from journald and is able to continue polling after journal
flush. Also reduced POLL_TIMEOUT a bit as it caused rsyslog to exit
with error in corner cases for some ppc when left at full second.
re-factored imjournal CI tests with journal_print tool to have more
detailed error reporting
When starting rsyslog with imjournal for first time it outputs
an error and plugin does not run because no state file exists yet.
Now it skips the loading and creates state file on first persist.
Also fixed imjournal tests to actually test plugin functionality.
