Very crude extension of Fluid 1 to read Fluid 2 files (and possibly w…

…rite them back as Fluid 1 files, but not Fluid 2!). Also, I started a README that points out the differences between FLTK 1 and FLTK 2 and tries to give some help in designing a downward compatible FLTK 3.

git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6912 ea41ed52-d2ee-0310-a9c1-e6b18d33e121

FL/Fl_Widget.H

@@ -148,7 +148,7 @@ protected:
         INVISIBLE       = 1<<1,   ///< the widget is not drawn but can receive events
         OUTPUT          = 1<<2,   ///< for output only
         NOBORDER        = 1<<3,   ///< don't draw a decoration (Fl_Window)
-        FORCE_POSITION  = 1<<4,   ///< don't let the window manager position thi window (Fl_Window)
+        FORCE_POSITION  = 1<<4,   ///< don't let the window manager position the window (Fl_Window)
         NON_MODAL       = 1<<5,   ///< thisis a hovering toolbar window (Fl_Window)
         SHORTCUT_LABEL  = 1<<6,   ///< the label contains a shortcut we need to draw
         CHANGED         = 1<<7,   ///< the widget value changed
@@ -160,6 +160,7 @@ protected:
         TOOLTIP_WINDOW  = 1<<13,  ///< a temporary popup, transparent to events, and dismissed easily (Fl_Window)
         MODAL           = 1<<14,  ///< a window blocking input to all other winows (Fl_Window)
         NO_OVERLAY      = 1<<15,  ///< window not using a hardware overlay plane (Fl_Menu_Window)
+        GROUP_RELATIVE  = 1<<16,  ///< position this idget relative to the parent group, not to the window
         // (space for more flags)
         USERFLAG3       = 1<<29,  ///< reserved for 3rd party extensions
         USERFLAG2       = 1<<30,  ///< reserved for 3rd party extensions