When user adds invalid auxilary parameter(s) to the smb.conf, pdbedit
invocations (or any utilty that ultimately calls lpcfg_map_parameter()),
will result in additional warning messages being printed even at DEBUG 0
on stdout. This may break parsing of output from the CLI utility, and in
the case of pdbedit, will prevent updating of user password.
This commit will change two things. First is a minimal workaround for the
passdb update to splitlines() and use only last element of resulting list.
Warnings in this specific situation are prepended to the command's output
and so will be safely discarded. Additionally, validation for smb_options
(auxiliary parameters for the SMB service) will be expanded to add a
call to LoadParm.dump_a_parameter(<aux param>). This function will raise
a RuntimeException if the parameter being queried does not exist in Samba's
internal param table.