FLUID: updates file structure README

fluid/README_fl.txt

@@ -313,6 +313,7 @@ The list of known Types and their inheritance is:
    |    |    +-- Fl_Table
    |    |    +-- Fl_Tabs
    |    |    +-- Fl_Scroll
+   |    |    +-- Fl_Terminal
    |    |    +-- Fl_Tile
    |    |    +-- Fl_Wizard
    |    |    +-- Fl_Grid
@@ -340,7 +341,6 @@ The list of known Types and their inheritance is:
    |    +-- Fl_File_Input
    |    +-- Fl_Text_Display
    |    +-- Fl_Text_Editor
-   |    |    +-- Fl_Simple_Terminal
    |    +-- Fl_Clock
    |    +-- Fl_Help_View
    |    +-- Fl_Progress

fluid/factory.cxx

@@ -853,6 +853,7 @@ class Fl_Terminal_Type : public Fl_Group_Type
   typedef Fl_Group_Type super;
 public:
   const char *type_name() FL_OVERRIDE { return "Fl_Terminal"; }
+  // Older .fl files with Fl_Simple_Terminal will create a Fl_Terminal instead.
   const char *alt_type_name() FL_OVERRIDE { return "Fl_Simple_Terminal"; }
   Fl_Widget *widget(int x, int y, int w, int h) FL_OVERRIDE {
     Fl_Widget *myo = 0L;