Split image widget into two definitions, default and centered (redo of d2191297c5)

data/gui/widget/image_default.cfg

@@ -7,6 +7,37 @@
 	id = "default"
 	description = "an image."
 
+	[resolution]
+
+		min_width = 0
+		min_height = 0
+
+		default_width = 0
+		default_height = 0
+
+		max_width = 0
+		max_height = 0
+
+		[state_enabled]
+
+			[draw]
+
+				[image]
+					name = "(text)"
+				[/image]
+
+			[/draw]
+
+		[/state_enabled]
+
+	[/resolution]
+
+[/image_definition]
+
+[image_definition]
+	id = "centered"
+	description = "an image."
+
 	[resolution]
 
 		min_width = 0
@@ -35,4 +66,3 @@
 	[/resolution]
 
 [/image_definition]
-

data/gui/window/mp_faction_select.cfg

@@ -86,7 +86,7 @@
 
 				{GUI_FORCE_WIDGET_MINIMUM_SIZE 144 144 (
 					[image]
-						definition = "default"
+						definition = "centered"
 						id = "leader_image"
 					[/image]
 				)}