add the JUNGLE terrain to Tiberian Dawn

http://cnc-comm.com/community/index.php?topic=2880.0

AUTHORS

@@ -17,7 +17,9 @@ Previous developers included:
     * Robert Pepperell (ytinasni)
 
 Also thanks to:
+    * Adam Valy (Tschokky)
     * Akseli Virtanen (RAGEQUIT)
+    * Allen262
     * Andrew Aldridge (i80and)
     * Andrew Perkins
     * Andrew Riedi

OpenRA.Mods.RA/Widgets/Logic/AssetBrowserLogic.cs

@@ -39,7 +39,7 @@ namespace OpenRA.Mods.RA.Widgets.Logic
 
 		readonly World world;
 
-		static readonly string[] AllowedExtensions = { ".shp", ".r8", "tmp", ".tem", ".des", ".sno", ".int" };
+		static readonly string[] AllowedExtensions = { ".shp", ".r8", "tmp", ".tem", ".des", ".sno", ".int", ".jun" };
 
 		[ObjectCreator.UseCtor]
 		public AssetBrowserLogic(Widget widget, Action onExit, World world)