Convert para_client to lopsub.

Convert para_client to lopsub.

This replaces the gengetopt command line parser for para_client by a
lopsub suite and links para_client against the lopsub library. The ggo
file for para_client was the last user of m4/gengetopt/complete.m4,
so this file can be removed.

The tricky part is create_merged_lpr(), which replaces
make_client_argv(). It is called from the i9e line handler and from
the completers. The new function merges the original parse result
with the arguments given at the command line to produce the parse
result stored in the client task structure.

The completers no longer duplicate the possible options each server
subcommand because the header file generated by lopsubgen exposes
an array of string literals which is suitable as the opts argument
of i9e_complete_option().