SWC: Support .png files in Show Pic/Movie specials

Author: SpaceManiac

source/supreme/display.cpp

@@ -154,7 +154,7 @@ TASK(void) ShowImageOrFlic(const char *str,byte nosnd,byte mode)
 	}
 
 	// BMP loading
-	if (!strcasecmp(extension, ".bmp"))
+	if (!strcasecmp(extension, ".bmp") || !strcasecmp(extension, ".png"))
 	{
 		EnterPictureDisplay();
 		if(!nosnd)

source/supreme/filedialog.cpp

@@ -36,7 +36,7 @@ static void ObtainFilenames(const char *dir, const char *ext)
 			extension = &str[dot];
 		}
 
-		if ((menuItems & FM_PICMOVIE) && !(!strcasecmp(extension, ".txt") || !strcasecmp(extension, ".bmp") || !strcasecmp(extension, ".flc")))
+		if ((menuItems & FM_PICMOVIE) && !(!strcasecmp(extension, ".txt") || !strcasecmp(extension, ".bmp") || !strcasecmp(extension, ".png") || !strcasecmp(extension, ".flc")))
 			continue;
 		if ((menuItems & FM_SOUNDS) && !(!strcasecmp(extension, ".wav") || !strcasecmp(extension, ".ogg")))
 			continue;