Command line debug options are now documented:
* --no-dlclose: do not call the function dlclose after plugins are unloaded
* --no-gnutls: do not call the init and deinit functions of GnuTLS library
* --no-gcrypt: do not call the init and deinit functions of Gcrypt library
These options must not be used in production, they're for debug only and can be
used with tools like Valgrind or electric-fence.
