Update API to work with the new two layer logo

data/core/help.cfg

@@ -95,7 +95,7 @@
     [topic]
         id=..introduction
         title= _ "Introduction"
-        text="<img>src=misc/logo.png align=middle box=no</img>" + _ "
+        text="<img>src=misc/logo-bg.png~BLIT(misc/logo.png) align=middle box=no</img>" + _ "
 
 <italic>text='Battle for Wesnoth'</italic> is a turn-based fantasy strategy game somewhat unusual among modern strategy games. While other games strive for complexity, <italic>text='Battle for Wesnoth'</italic> strives for simplicity of both rules and gameplay. This does not make the game simple, however — from these simple rules arise a wealth of strategy, making the game easy to learn but a challenge to master.
 

data/gui/default/window/title_screen.cfg

@@ -306,6 +306,32 @@
 
 						[stack]
 
+							[layer]
+
+								[row]
+									grow_factor = 0
+
+									{_GUI_V_SPACER 30}
+
+								[/row]
+
+								[row]
+									grow_factor = 1
+
+									[column]
+										vertical_alignment = "top"
+
+										[image]
+											id = "logo-bg"
+											label = "misc/logo-bg.png"
+										[/image]
+
+									[/column]
+
+								[/row]
+
+							[/layer]
+
 							[layer]
 
 								[row]

src/loadscreen.cpp

@@ -71,9 +71,9 @@ loadscreen::loadscreen(CVideo &screen, const int percent):
 	screen_(screen),
 	textarea_(),
 #ifdef SDL_GPU
-	logo_image_(image::get_texture("misc/logo.png")),
+	logo_image_(image::get_texture("misc/logo-bg.png~BLIT(misc/logo.png)")),
 #else
-	logo_surface_(image::get_image("misc/logo.png")),
+	logo_surface_(image::get_image("misc/logo-bg.png~BLIT(misc/logo.png)")),
 #endif
 	logo_drawn_(false),
 	pby_offset_(0),