Add missing opacity attribute for Text3D. Prevent illegal index access when amount of text batches is in mismatch with amount of Drawable batches. Closes #1350.

Source/Urho3D/UI/Text3D.cpp

@@ -87,6 +87,7 @@ void Text3D::RegisterObject(Context* context)
         horizontalAlignments, HA_LEFT, AM_DEFAULT);
     URHO3D_ENUM_ACCESSOR_ATTRIBUTE("Vert Alignment", GetVerticalAlignment, SetVerticalAlignment, VerticalAlignment, verticalAlignments,
         VA_TOP, AM_DEFAULT);
+    URHO3D_ACCESSOR_ATTRIBUTE("Opacity", GetOpacity, SetOpacity, float, 1.0f, AM_FILE);
     URHO3D_ACCESSOR_ATTRIBUTE("Color", GetColorAttr, SetColor, Color, Color::WHITE, AM_DEFAULT);
     URHO3D_ATTRIBUTE("Top Left Color", Color, text_.color_[0], Color::WHITE, AM_DEFAULT);
     URHO3D_ATTRIBUTE("Top Right Color", Color, text_.color_[1], Color::WHITE, AM_DEFAULT);
@@ -146,7 +147,7 @@ void Text3D::UpdateGeometry(const FrameInfo& frame)
 
     if (geometryDirty_)
     {
-        for (unsigned i = 0; i < batches_.Size(); ++i)
+        for (unsigned i = 0; i < batches_.Size() && i < uiBatches_.Size(); ++i)
         {
             Geometry* geometry = geometries_[i];
             geometry->SetDrawRange(TRIANGLE_LIST, 0, 0, uiBatches_[i].vertexStart_,