6866243: Javadoc for java.lang.Character still refers to Unicode 4 instead of 5

Reviewed-by: okutsu

src/share/classes/java/lang/Character.java

@@ -38,7 +38,7 @@ import java.util.Locale;
  * a character's category (lowercase letter, digit, etc.) and for converting
  * characters from uppercase to lowercase and vice versa.
  * <p>
- * Character information is based on the Unicode Standard, version 4.0.
+ * Character information is based on the Unicode Standard, version 5.1.0.
  * <p>
  * The methods and data of class <code>Character</code> are defined by
  * the information in the <i>UnicodeData</i> file that is part of the