Mike's new isis_fancy_plots incorporated; users can still decide when they want to switch

As the plot functions had been changed in a non-backwards-compatible way,
special care was taken not to overwrite the old functions for users relying on them.

Unless `isisscripts_use_fancy_plots_v1' is defined in the global name space
-- e.g., by having

   public variable isisscripts_use_fancy_plots_v1;

in your ~/.isisrc --,
`require("isisscripts");' will still provide the old plot functions
for users that are not yet ready to make the leap to isis_fancy_plots v.1.