Convert para_fade to lopsub.

Convert para_fade to lopsub.

This replaces the ggo file for the command line and config file parser
of para_fade by a lopsub suite file and links para_fade against the
lopsub library.

As there are no subcommands, the conversion is straight forward and
the bulk of the patch are simple changes which replace access to the
gengetopt structure by equivalent lopsub constructs.