Add support for HistoryBackButton and HistoryForwardButton

This resolves TDE/tdebase#421.

Signed-off-by: Mavridis Philippe <mavridisf@gmail.com>
(cherry picked from commit aec0061106)

src/kernel/ntqnamespace.h

@@ -74,17 +74,19 @@ public:
 
     // documented in qevent.cpp
     enum ButtonState {				// mouse/keyboard state values
-	NoButton	= 0x0000,
-	LeftButton	= 0x0001,
-	RightButton	= 0x0002,
-	MidButton	= 0x0004,
-	MouseButtonMask = 0x0007,
-	ShiftButton	= 0x0100,
-	ControlButton   = 0x0200,
-	AltButton	= 0x0400,
-	MetaButton	= 0x0800,
-	KeyButtonMask	= 0x0f00,
-	Keypad		= 0x4000
+	NoButton	     = 0x0000,
+	LeftButton	     = 0x0001,
+	RightButton	     = 0x0002,
+	MidButton	     = 0x0004,
+	HistoryBackButton    = 0x0008,
+	HistoryForwardButton = 0x0010,
+	MouseButtonMask      = 0x001f,
+	ShiftButton	     = 0x0100,
+	ControlButton        = 0x0200,
+	AltButton	     = 0x0400,
+	MetaButton	     = 0x0800,
+	KeyButtonMask	     = 0x0f00,
+	Keypad		     = 0x4000
     };
 
     // documented in qobject.cpp

src/kernel/qapplication_x11.cpp

@@ -4228,6 +4228,10 @@ bool TQETWidget::translateMouseEvent( const XEvent *event )
 		translateWheelEvent( globalPos.x(), globalPos.y(), delta, state, (hor)?Horizontal:Vertical );
 	    }
 	    return TRUE;
+
+        // history navigation buttons
+        case 8: button = HistoryBackButton; break;
+        case 9: button = HistoryForwardButton; break;
 	}
 	if ( event->type == ButtonPress ) {	// mouse button pressed
 #if defined(Q_OS_IRIX) && defined(QT_TABLET_SUPPORT)

src/kernel/qevent.cpp

@@ -91,6 +91,8 @@
     the right button on left-handed mice.)
     \value RightButton  the right button.
     \value MidButton  the middle button.
+    \value HistoryBackButton  history navigation back button.
+    \value HistoryForwardButton  history navigation forward button.
     \value ShiftButton  a Shift key on the keyboard is also pressed.
     \value ControlButton  a Ctrl key on the keyboard is also pressed.
     \value AltButton  an Alt key on the keyboard is also pressed.
@@ -98,7 +100,8 @@
     \value Keypad  a keypad button is pressed.
     \value KeyButtonMask a mask for ShiftButton, ControlButton,
     AltButton and MetaButton.
-    \value MouseButtonMask a mask for LeftButton, RightButton and MidButton.
+    \value MouseButtonMask a mask for LeftButton, RightButton, MidButton,
+    HistoryBackButton and HistoryForwardButton.
 */
 
 /*!