Add libsmbclient's print-related functions

[aklomp]

Libsmbclient has various functions for printing to print shares, getting print queues and so on. We should add them, because it's easy to do so within the framework that we have and because it's the last large bit of upstream functionality we don't expose.

[eduardok]

Yes, I always hope to get back and add all the functions, but never had time. Will try starting next week.