This could lead to segfaults. Triggering condition: multiple action
instances using ommysql.  Thanks to Tomas Heinrich for reporting this
problem and providing an initial patch (which my solution is based on,
I need to add more code to clean the mess up).

after getting OK via email from contributor Ariel P. (2012-02-02 22:06 CET)

The capability has been added for module to specify that they do not
like being unloaded.
related bug tracker: http://bugzilla.adiscon.com/show_bug.cgi?id=222

Signed-off-by: Rainer Gerhards <rgerhards@adiscon.com>

Signed-off-by: Rainer Gerhards <rgerhards@adiscon.com>

... by moving code to stream.c. Thanks to the new design, new cases are
not really needed, resulting in cleaner code.

I also did a cleanup of header file usage as a side-activity.

Remove AC_CHECK_HEADERS([mysql/mysql.h],...) as this was causing pain
for users where the mysql headers are not installed in the system include
directory. It was superfluous anyways, as we check for mysql_config and
set the include path to the correct directory.
Update ommysql.c to use #include <mysql.h>, as mysql_config will set the
include path to /path/to/include/mysql/ so <mysql/mysql.h> would not
work.
Remove errmsg.h include as it is not used.

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.

Conflicts:

	ChangeLog
	configure.ac
	doc/manual.html
	plugins/imuxsock/imuxsock.c