Clean up header dependencies in the vncviewer directory
diff --git a/vncviewer/OptionsDialog.h b/vncviewer/OptionsDialog.h
index b3ac015..a6b504e 100644
--- a/vncviewer/OptionsDialog.h
+++ b/vncviewer/OptionsDialog.h
@@ -22,11 +22,14 @@
#include <map>
#include <FL/Fl_Window.H>
-#include <FL/Fl_Group.H>
-#include <FL/Fl_Check_Button.H>
-#include <FL/Fl_Round_Button.H>
-#include <FL/Fl_Int_Input.H>
-#include <FL/Fl_Choice.H>
+
+class Fl_Widget;
+class Fl_Group;
+class Fl_Check_Button;
+class Fl_Round_Button;
+class Fl_Input;
+class Fl_Int_Input;
+class Fl_Choice;
typedef void (OptionsCallback)(void*);