Conflicts:
	ChangeLog
	configure.ac
	doc/manual.html
	runtime/debug.c
	runtime/stream.c
	tests/Makefile.am
	tests/diskqueue.sh
	tests/nettester.c
	tools/omfile.c

this is a perquisite to support more flexible testing modes, which
could not intelligently be implemented with the old interface

disk queue mode did no longer work correctly. A side-effect of
this commit here is slightly cleaned-up (and more elegant) code
for circular files.

- added a test to check handling of damaged .qi files on startup
- made sure each test identifies itself on startup

this permits us to keep a persistent test environment between
v4 and v5, most importantly using the same tools. As far as the
actual tests are concerned, some had issues. I had no time to check
if that was an issue with the test or an actual issue with the
v3/4 engine. Will do that at some later stage.

The imdiag module now can very effectively inject messages, which also
frees us from uncertainties of tcp reception and processing. All shell
script based tests have been modularized, what makes it far easier to
create new tests. Also, the test bench now executes more reliable and
much faster, because we can now rely on actual engine information where
we previously did just a dumb sleep.

imdiag/imtcp had a modload race condition (as imdiag is a testing aid,
this has no implications for production deployments). Also, I replaced
netcat by a custom program to talk to imdiag. This, for the first time ever,
is now a Java program. I plan to add some GUI troubleshooting tools and
thought it is a good idea to start doing things in Java that can simply
be done in that language.