MVStore: move background exception listener and page size to the builder

h2/src/test/org/h2/test/store/TestConcurrent.java

@@ -174,8 +174,7 @@ public class TestConcurrent extends TestMVStore {
     }
 
     private void testConcurrentIterate() {
-        MVStore s = new MVStore.Builder().open();
-        s.setPageSize(3);
+        MVStore s = new MVStore.Builder().pageSize(3).open();
         final MVMap<Integer, Integer> map = s.openMap("test");
         final int len = 10;
         final Random r = new Random();