permits to specify how many TCP servers shall be possible (default is 20).

... as well as added multi-ruleset support for imtcp

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.

Well, actually this and a lot of related things. I improved the
testbench so that the new capabilities are automatically tested and
also did some general cleanup. The current multiple tcp listener
solution will probably receive some further cleanup, too, but looks
quite OK so far. I also reviewed the way tcpsrv et all work, in
preparation of using this code for imdiag. I need to document the
findings, especially as the code is rather complicated "thanks" to
the combination of plain tcp and gssapi transport modes.

Conflicts:
	ChangeLog
	tcpsrv.c
	tcpsrv.h

Note: we have a slight inconsistency, as interface version v4 was already
used for tcpsrv in this branch. We accept this inconsistency.

Conflicts:
	ChangeLog

This resulted in a fixed upper limit of 200 connections.

Conflicts:
	ChangeLog
	Makefile.am
	configure.ac
	doc/manual.html

pkg-config uses uppercase for its _CFLAGS and _LIBS variable names.
So we follow suit and convert all _cflags and _libs variables to
uppercase for more consistency.