utils unixsock: Added sc_unixsock_client_process_lines().

This function may be used to process data returned from the socket line by
line. The function will split each line into columns. The data-types of each
column may be specified by the caller.

This is similar to the DBI query abstraction function (sc_dbi_exec_query()) in
that in takes care of all the annoying data parsing and conversion stuff.