CONF_modules_free() closes down and frees up all memory allocated by all
configuration modules.
CONF_modules_finish() calls each configuration modules finish handler
to free up any configuration that module may have performed.
CONF_modules_unload() finishes and unloads configuration modules. If
all is set to 0 only modules loaded from DSOs will be unloads. If
all is 1 all modules, including builtin modules will be unloaded.
NOTES
Normally applications will only call CONF_modules_free() at application to
tidy up any configuration performed.