Enable disallowBatchOnCascade per DatabasePlatform (added for SQL Server)

src/main/java/com/avaje/ebean/config/ServerConfig.java

@@ -1828,4 +1828,16 @@ public class ServerConfig {
     }
     return hitList;
   }
+
+  /**
+   * Return the PersistBatch mode to use for 'batchOnCascade' taking into account if the database
+   * platform supports getGeneratedKeys in batch mode.
+   * <p>
+   * Used to effectively turn off batchOnCascade for SQL Server - still allows explicit batch mode.
+   * </p>
+   */
+  public PersistBatch appliedPersistBatchOnCascade() {
+
+    return databasePlatform.isDisallowBatchOnCascade() ? PersistBatch.NONE : persistBatchOnCascade;
+  }
 }

src/main/java/com/avaje/ebeaninternal/server/transaction/TransactionManager.java

@@ -106,7 +106,7 @@ public class TransactionManager {
 	      BeanDescriptorManager descMgr, BootupClasses bootupClasses) {
 
     this.persistBatch = config.getPersistBatch();
-    this.persistBatchOnCascade = config.getPersistBatchOnCascade();
+    this.persistBatchOnCascade = config.appliedPersistBatchOnCascade();
 		this.beanDescriptorManager = descMgr;
 		this.clusterManager = clusterManager;
 		this.serverName = config.getName();