Update documented Java requirements from 4 to 5, as noted in HADOOP-584.

git-svn-id: https://svn.apache.org/repos/asf/lucene/hadoop/trunk@454809 13f79535-47bb-0310-9956-ffa450edef68

src/java/overview.html

@@ -16,7 +16,7 @@ href="org/apache/hadoop/mapred/package-summary.html">org.apache.hadoop.mapred
 
 <ol>
   
-<li>Java 1.4.x, preferably from <a
+<li>Java 1.5.x, preferably from <a
  href="http://java.sun.com/j2se/downloads.html">Sun</a> Set
  <tt>JAVA_HOME</tt> to the root of your Java installation.</li>