More precise enum definition

Author: garydgregory

src/main/java/org/apache/commons/io/IOCase.java

@@ -63,7 +63,7 @@ public enum IOCase {
      * versa, then the value of the case-sensitivity flag will change.
      * </p>
      */
-    SYSTEM("System", !FilenameUtils.isSystemWindows());
+    SYSTEM("System", FileSystem.getCurrent().isCaseSensitive());
 
     /** Serialization version. */
     private static final long serialVersionUID = -6343169151696340687L;