This enables us to use more efficient calling conventions and
also helps us keep the on-disk structure of a msg object more
consistent in future releases.

I tried to work too quick this morning. A side-effect of an
earlier change was that no UDP messages were parsed, which
lead to their loss, because no PRI was set in this case.

Message parsing is now done as part of main message queue worker
processing (was part of the input thread) This should also improve
performance, as potentially more work is done in parallel.

cleaned up previous code and redid it in a way that makes
it much easier to extend it

also added a new macro DBGPRINTF which is a performance-optimzed
version of dbgprintf

This enhances performance and, as some have pointed out, is
probably also more consistent with what users expect how
the various output-timestamp related function should work. This
commit needs some more testing.

...which enables to work with
less acurate timestamps in favor of performance. This enables querying
of the time only every n-th time if imudp is running in the tight
receive loop (aka receiving messsages at a high rate)

removed code not actually needed in imupd