Bug 20580: Make create_superlibrarian.pl accept parameters

Bug 20580: Make create_superlibrarian.pl accept parameters

So far this script does not accept parameters and create a koha/koha
superlibrarian
This patch makes it accept parameters to create a customized
superlibrarian patrons.

Test plan:
Use the script with valid and invalid paramters and confirm that it
works as expected.

Note: A cryptic "Invalid parameter passed" error is raised when the
categorycode is not valid. Better error handling must be provided but
Koha::Exceptions seems to be enhancement (see related bug reports).

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>