Fix some gui interface bugs:

1. Fix credits fading effect

2. Display have many no of (addons mostly) arenas are hidden due to
   missing of navigation mesh

3. Fix wrong size of kart stats bar

src/guiengine/scalable_font.cpp

@@ -1002,12 +1002,12 @@ void ScalableFont::doDraw(const core::stringw& text,
 
         if (fallback[n] || m_type == T_BOLD)
         {
-            video::SColor title_colors[] = {GUIEngine::getSkin()->getColor("font::top"   ),
+            video::SColor top = GUIEngine::getSkin()->getColor("font::top");
-                                            GUIEngine::getSkin()->getColor("font::bottom"),
+            video::SColor bottom = GUIEngine::getSkin()->getColor("font::bottom");
-                                            GUIEngine::getSkin()->getColor("font::top"   ),
+            top.setAlpha(color.getAlpha());
-                                            GUIEngine::getSkin()->getColor("font::bottom")
+            bottom.setAlpha(color.getAlpha());
-                                           };
 
+            video::SColor title_colors[] = {top, bottom, top, bottom};
             if (charCollector != NULL)
             {
                 charCollector->collectChar(texture,

src/guiengine/widgets/dynamic_ribbon_widget.cpp

@@ -46,6 +46,8 @@ DynamicRibbonWidget::DynamicRibbonWidget(const bool combo, const bool multi_row)
     m_supports_multiplayer = true;
     m_scrolling_enabled    = true;
     m_animated_contents    = false;
+    // Don't initialize m_font here to make lazy loading characters work
+    m_font                 = NULL;
 
     // by default, set all players to have no selection in this ribbon
     for (unsigned int n=0; n<MAX_PLAYER_COUNT; n++)
@@ -730,6 +732,16 @@ void DynamicRibbonWidget::onRibbonWidgetScroll(const int delta_x)
 
 // -----------------------------------------------------------------------------
 
+void DynamicRibbonWidget::setText(const wchar_t *text)
+{
+    Widget::setText(text);
+
+    if (m_label != NULL)
+        m_label->setText(text);
+}
+
+// -----------------------------------------------------------------------------
+
 void DynamicRibbonWidget::onRibbonWidgetFocus(RibbonWidget* emitter, const int playerID)
 {
     if (m_deactivated) return;

src/guiengine/widgets/dynamic_ribbon_widget.hpp

@@ -302,6 +302,8 @@ namespace GUIEngine
         /** \brief callback from IRibbonListener */
         virtual void onSelectionChange(){}
 
+        virtual void setText(const wchar_t *text);
+
         virtual void update(float delta);
 
         /** Set approximately how many items are expected to be in this ribbon; will help the layout

src/guiengine/widgets/kart_stats_widget.cpp

@@ -39,6 +39,7 @@ KartStatsWidget::KartStatsWidget(core::recti area, const int player_id,
                                  std::string kart_group, bool multiplayer,
                                  bool display_text) : Widget(WTYPE_DIV)
 {
+    m_title_font = !multiplayer;
     m_player_id = player_id;
 
     const std::string default_kart = UserConfigParams::m_default_kart;
@@ -153,7 +154,7 @@ void KartStatsWidget::setSize(const int x, const int y, const int w, const int h
 
     // -- sizes
     m_skill_bar_w = w;
-    m_skill_bar_h = GUIEngine::getTitleFontHeight();
+    m_skill_bar_h = (m_title_font ? GUIEngine::getTitleFontHeight() : GUIEngine::getFontHeight());
 
     // for shrinking effect
     if (h < 175)

src/states_screens/arenas_screen.cpp

@@ -218,6 +218,7 @@ void ArenasScreen::buildTrackList()
 
     bool soccer_mode = race_manager->getMinorMode() == RaceManager::MINOR_MODE_SOCCER;
     bool arenas_have_navmesh = false;
+    int skipped = 0;
 
     if (curr_group_name == ALL_ARENA_GROUPS_ID)
     {
@@ -276,8 +277,11 @@ void ArenasScreen::buildTrackList()
                   (!(curr->hasNavMesh()                  ||
                   race_manager->getNumLocalPlayers() > 1 ||
                   UserConfigParams::m_artist_debug_mode)))
+                {
+                    skipped++;
                     continue;
                 }
+            }
 
             if (PlayerManager::getCurrentPlayer()->isLocked(curr->getIdent()))
             {
@@ -291,12 +295,13 @@ void ArenasScreen::buildTrackList()
             }
         }
     }
-    if (arenas_have_navmesh || race_manager->getNumLocalPlayers() > 1 ||
+    if ((arenas_have_navmesh || race_manager->getNumLocalPlayers() > 1 ||
-        UserConfigParams::m_artist_debug_mode)
+        UserConfigParams::m_artist_debug_mode) && !skipped)
         w->addItem(_("Random Arena"), "random_track", "/gui/track_random.png");
     w->updateItemDisplay();
 
-    assert(w->getItems().size() > 0);
+    if (skipped > 0)
+        w->setText( _("%i arenas unavailable in single player", skipped) );
 }
 
 // ------------------------------------------------------------------------------------------------------