Add serialVersionUID to avoid warnings from some compilers

h2/src/main/org/h2/mvstore/tx/VersionedBitSet.java

@@ -11,8 +11,9 @@ import java.util.BitSet;
  * Class VersionedBitSet extends standard BitSet to add a version field.
  * This will allow bit set and version to be changed atomically.
  */
-final class VersionedBitSet extends BitSet
-{
+final class VersionedBitSet extends BitSet {
+    private static final long serialVersionUID = 1L;
+
     private long version;
 
     public VersionedBitSet() {}

h2/src/main/org/h2/security/auth/AuthConfigException.java

@@ -10,6 +10,7 @@ package org.h2.security.auth;
  *
  */
 public class AuthConfigException extends RuntimeException {
+    private static final long serialVersionUID = 1L;
 
     public AuthConfigException() {
         super();

h2/src/main/org/h2/security/auth/AuthenticationException.java

@@ -9,6 +9,7 @@ package org.h2.security.auth;
  * Exception thrown in case of errors during authentication
  */
 public class AuthenticationException extends Exception {
+    private static final long serialVersionUID = 1L;
 
     public AuthenticationException() {
         super();