Delete an improper stringToLower() call in sprite file handling. This patch removes a stringToLower() call in the sprite file loader which breaks access to sprite data on Linux if the containing directory's pathname has any uppercase letters.

--- a/BBGE/SkeletalSprite.cpp	Sun Feb 13 11:31:37 2011 +0900
+++ b/BBGE/SkeletalSprite.cpp	Sun Apr 03 02:02:53 2011 +0900
@@ -1290,8 +1290,6 @@
 		return;
 	}
 
-	stringToLower(file);
-
 	loaded = true;
 	
 	TiXmlDocument xml;