Reverting commit e34f50dd10 as per Gilles request.

The work on revamping the random packages is perfoemd in the random-ravamp branch.

src/main/java/org/apache/commons/math4/random/AbstractWell.java

@@ -38,7 +38,7 @@ public abstract class AbstractWell
     extends BaseRandomGenerator
     implements Serializable {
     /** Serializable version identifier. */
-    private static final long serialVersionUID = 20151228L;
+    private static final long serialVersionUID = 20150228L;
     /** Current index in the bytes pool. */
     protected int index;
     /** Bytes pool. */