replace framebuffer.h include with forward declaration

instead of including framebuffer.h almost everywhere, replace it with
class CFrameBuffer forward declarations and/or generic system includes.
Add a hack to define fb_pixel_t to config.h (one reason for
framebuffer.h includes was the fb_pixel_t define)


Origin commit data
------------------
Commit: e490f84ea8
Author: Stefan Seyfried <seife@tuxbox-git.slipkontur.de>
Date: 2017-02-05 (Sun, 05 Feb 2017)

src/gui/widget/buttons.h

@@ -23,7 +23,6 @@
  */
  
 #include <driver/fontrenderer.h>
-#include <driver/framebuffer.h>
 #include <system/localize.h>
 #include <gui/color.h>
 

src/gui/widget/colorchooser.h

@@ -33,12 +33,12 @@
 #ifndef __colorchooser__
 #define __colorchooser__
 
-#include <driver/framebuffer.h>
 #include <system/localize.h>
 #include <gui/widget/menue.h>
 
 #include <string>
 
+class CFrameBuffer;
 class CColorChooser : public CMenuTarget
 {
 	private:

src/gui/widget/keyboard_input.h

@@ -26,7 +26,6 @@
 
 #include "menue.h"
 
-#include <driver/framebuffer.h>
 #include <system/localize.h>
 
 #include <string>
@@ -41,6 +40,7 @@ struct keyboard_layout
         std::string (*keys)[KEY_ROWS][KEY_COLUMNS];
 };
 
+class CFrameBuffer;
 class CInputString
 {
 	private:

src/gui/widget/keychooser.h

@@ -35,14 +35,13 @@
 
 #include <string>
 
-#include <driver/framebuffer.h>
 #include <driver/fontrenderer.h>
 #include <driver/rcinput.h>
 #include <system/localize.h>
 
 #include "menue.h"
 
-
+class CFrameBuffer;
 class CKeyChooserItem;
 class CKeyChooserItemNoKey;
 class CKeyChooser : public CMenuWidget

src/gui/widget/listbox.h

@@ -28,10 +28,9 @@
 #include "menue.h"
 #include "listhelpers.h"
 
-#include <driver/framebuffer.h>
-
 #include <string>
 
+class CFrameBuffer;
 class CListBox : public CMenuTarget, public CListHelpers
 {
 	protected:

src/gui/widget/menue.h

@@ -36,12 +36,10 @@
 #ifndef __MENU__
 #define __MENU__
 
-#include <driver/framebuffer.h>
 #include <driver/rcinput.h>
 #include <system/localize.h>
 #include <gui/widget/buttons.h>
 #include <gui/widget/icons.h>
-#include <gui/color.h>
 #include <gui/plugins.h>
 #include <gui/components/cc.h>
 #include <string>
@@ -58,6 +56,8 @@ extern "C" {
 
 typedef int mn_widget_id_t;
 typedef int menu_item_disable_cond_t;
+
+class CFrameBuffer;
 class CMenuWidget;
 struct menu_return
 {

src/gui/widget/mountchooser.h

@@ -33,7 +33,6 @@
 #ifndef __mountchooser__
 #define __mountchooser__
 
-#include <driver/framebuffer.h>
 #include <system/localize.h>
 #include <gui/widget/menue.h>
 

src/gui/widget/stringinput.h

@@ -28,11 +28,11 @@
 
 #include "menue.h"
 
-#include <driver/framebuffer.h>
 #include <system/localize.h>
 
 #include <string>
 
+class CFrameBuffer;
 class CStringInput : public CMenuTarget
 {
 	protected:

src/gui/widget/stringinput_ext.h

@@ -35,12 +35,12 @@
 
 #include "menue.h"
 
-#include <driver/framebuffer.h>
 #include <system/localize.h>
 
 #include <string>
 #include <vector>
 
+class CFrameBuffer;
 class CExtendedInput_Item;
 class CExtendedInput : public CMenuTarget
 {