New transparant button in transparent dialog.

The art might need some more polishing, but rather leave that to an artist.

data/gui/default/widget/button_default.cfg

@@ -99,4 +99,15 @@
 
 [/button_definition]
 
+[button_definition]
+
+	id = "transparent"
+	description = "Default transparent button"
+
+	# Tiny gui sizes haven't been tested yet so might need some tuning.
+	{_GUI_RESOLUTION ({GUI_TINY__RESOLUTION}) 20  54 11  6 2 ({GUI_TINY__FONT_SIZE__SMALL})   "button_transparent" }
+	{_GUI_RESOLUTION ()                       40 108 22 13 4 ({GUI_NORMAL__FONT_SIZE__SMALL}) "button_transparent" }
+
+[/button_definition]
+
 #undef _GUI_RESOLUTION 

data/gui/default/window/wml_message.cfg

@@ -447,7 +447,7 @@
 																# whether or not a scrollbar is needed to show the
 																# text.
 																id = "ok"
-																definition = "default"
+																definition = "transparent"
 
 																label = _ "OK"
 															[/button]