Fixed: we don't need to reload ResourceImages, because they can't be unloaded...

Fixed: we don't need to reload ResourceImages, because they can't be unloaded and reloading them can cause problems when trying to display them in PictureBoxes.
Removed Sector Brightness Mode keyboard binding from the default program configuration file.

Build/GZBuilder.default.cfg

@@ -53,7 +53,6 @@ shortcuts
 	buildermodes_fliplinedefs = 70;
 	buildermodes_joinsectors = 74;
 	buildermodes_removepoint = 8;
-	buildermodes_brightnessmode = 65602;
 	buildermodes_mergesectors = 65610;
 	buildermodes_splitlinedefs = 0;
 	buildermodes_visualmode = 87;

Source/Core/Data/ResourceImage.cs

@@ -30,8 +30,8 @@ namespace CodeImp.DoomBuilder.Data
 		#region ================== Variables
 
 		// Image source
-		private Assembly assembly;
-		private string resourcename;
+		private readonly Assembly assembly;
+		private readonly string resourcename;
 
 		#endregion
 
@@ -71,15 +71,15 @@ namespace CodeImp.DoomBuilder.Data
 		// This loads the image
 		protected override void LocalLoadImage()
 		{
-			Stream bitmapdata;
-
+			if(IsImageLoaded) return; //mxd. ResourceImages can't be unloaded, so no need to reload them.
+			
 			lock(this)
 			{
 				// No failure checking here. If anything fails here, it is not the user's fault,
 				// because the resources this loads are in the assembly.
 				
 				// Get resource from memory
-				bitmapdata = assembly.GetManifestResourceStream(resourcename);
+				Stream bitmapdata = assembly.GetManifestResourceStream(resourcename);
 				if(bitmap != null) bitmap.Dispose();
 				bitmap = (Bitmap)Image.FromStream(bitmapdata);
 				bitmapdata.Dispose();