Docs: use // for comments in examples

Without sgml mode, we can't escape /* as /* anymore,
so just switch to // for comments in examples.

gdk/gdk.c

@@ -673,14 +673,14 @@ gdk_threads_dispatch_free (gpointer data)
  * static gboolean
  * idle_callback (gpointer data)
  * {
- *    /* gdk_threads_enter(); would be needed for g_idle_add() */
+ *    // gdk_threads_enter(); would be needed for g_idle_add()
  *
  *    SomeWidget *self = data;
- *    /* do stuff with self */
+ *    // do stuff with self
  *
  *    self->idle_id = 0;
  *
- *    /* gdk_threads_leave(); would be needed for g_idle_add() */
+ *    // gdk_threads_leave(); would be needed for g_idle_add()
  *    return FALSE;
  * }
  *
@@ -688,7 +688,7 @@ gdk_threads_dispatch_free (gpointer data)
  * some_widget_do_stuff_later (SomeWidget *self)
  * {
  *    self->idle_id = gdk_threads_add_idle (idle_callback, self)
- *    /* using g_idle_add() here would require thread protection in the callback */
+ *    // using g_idle_add() here would require thread protection in the callback
  * }
  *
  * static void
@@ -780,7 +780,7 @@ gdk_threads_add_idle (GSourceFunc    function,
  * {
  *    SomeWidget *self = data;
  *    
- *    /* do stuff with self */
+ *    // do stuff with self
  *    
  *    self->timeout_id = 0;
  *    

gdk/gdkdisplaymanager.c

@@ -91,14 +91,14 @@
  * #ifdef GDK_WINDOWING_X11
  *   if (GDK_IS_X11_DISPLAY (display))
  *     {
- *       /* make X11-specific calls here */
+ *       // make X11-specific calls here
  *     }
  *   else
  * #endif
  * #ifdef GDK_WINDOWING_QUARTZ
  *   if (GDK_IS_QUARTZ_DISPLAY (display))
  *     {
- *       /* make Quartz-specific calls here */
+ *       // make Quartz-specific calls here
 *     }
  *   else
  * #endif

gdk/gdkevents.c

@@ -1678,11 +1678,11 @@ gdk_event_get_source_device (const GdkEvent *event)
  *
  * |[<!-- language="C" -->
  * {
- *   /&ast; motion_event handler &ast;/
+ *   // motion_event handler
  *   x = motion_event->x;
  *   y = motion_event->y;
- *   /&ast; handle (x,y) motion &ast;/
- *   gdk_event_request_motions (motion_event); /&ast; handles is_hint events &ast;/
+ *   // handle (x,y) motion
+ *   gdk_event_request_motions (motion_event); // handles is_hint events
  * }
  * ]|
  *

gdk/gdkkeys.c

@@ -501,14 +501,14 @@ gdk_keymap_lookup_key (GdkKeymap          *keymap,
  * `<Control>plus` accelerator `<Shift>` should be masked out.
  *
  * |[<!-- language="C" -->
- * /&ast; We want to ignore irrelevant modifiers like ScrollLock &ast;/;
+ * // We want to ignore irrelevant modifiers like ScrollLock
  * #define ALL_ACCELS_MASK (GDK_CONTROL_MASK | GDK_SHIFT_MASK | GDK_MOD1_MASK)
  * gdk_keymap_translate_keyboard_state (keymap, event->hardware_keycode,
  *                                      event->state, event->group,
  *                                      &keyval, NULL, NULL, &consumed);
  * if (keyval == GDK_PLUS &&
  *     (event->state & ~consumed & ALL_ACCELS_MASK) == GDK_CONTROL_MASK)
- *   /&ast; Control was pressed &ast;/
+ *   // Control was pressed
  * ]|
  * 
  * An older interpretation @consumed_modifiers was that it contained
@@ -516,10 +516,10 @@ gdk_keymap_lookup_key (GdkKeymap          *keymap,
  * this allowed accelerators to be stored with irrelevant consumed
  * modifiers, by doing:
  * |[<!-- language="C" -->
- * /&ast; XXX Don’t do this XXX &ast;/
+ * // XXX Don’t do this XXX
  * if (keyval == accel_keyval &&
  *     (event->state & ~consumed & ALL_ACCELS_MASK) == (accel_mods & ~consumed))
- *   /&ast; Accelerator was pressed &ast;/
+ *   // Accelerator was pressed
  * ]|
  *
  * However, this did not work if multi-modifier combinations were

gdk/wayland/gdkdisplay-wayland.c

@@ -52,14 +52,14 @@
  * #ifdef GDK_WINDOWING_WAYLAND
  *   if (GDK_IS_WAYLAND_DISPLAY (display))
  *     {
- *       /* make Wayland-specific calls here */
+ *       // make Wayland-specific calls here
  *     }
  *   else
  * #endif
  * #ifdef GDK_WINDOWING_X11
  *   if (GDK_IS_X11_DISPLAY (display))
  *     {
- *       /* make X11-specific calls here */
+ *       // make X11-specific calls here
  *     }
  *   else
  * #endif

gdk/x11/gdkmain-x11.c

@@ -64,14 +64,14 @@
  * #ifdef GDK_WINDOWING_X11
  *   if (GDK_IS_X11_DISPLAY (display))
  *     {
- *       /* make X11-specific calls here */
+ *       // make X11-specific calls here
  *     }
  *   else
  * #endif
  * #ifdef GDK_WINDOWING_QUARTZ
  *   if (GDK_IS_QUARTZ_DISPLAY (display))
  *     {
- *       /* make Quartz-specific calls here &ast/
+ *       // make Quartz-specific calls here
  *     }
  *   else
  * #endif