LegendTitle:

--------------------------------------------------------------------------
   Add a title to the current legend.
   The title will be bold. The default font size is 12.
--------------------------------------------------------------------------
   Form:
   LegendTitle( name, size )
--------------------------------------------------------------------------

   -------
   Inputs
   -------
   name  (1,:)    Title
   size  (1,1)    Fontsize

   -------
   Outputs
   -------
   None

------------------------------------------------------------------------