Remove the possible feature add_instances

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>
Add data type to sqlite plugin table

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>
Execute module->init/exit when loading/unloading

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>
Remove warning

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>
Helper functions for check_stderr plugin functions

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>
Plugin helper functions

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>
Generic standard error check

Signed-off-by: Markus Pargmann <mpargmann@allfex.org>